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Analytical and Bioanalytical Chemistry (v.397, #1)

Avogadro constant challenge by William B. Jensen; Juris Meija (pp. 1-2).

Solution to the beryllium valence challenge by Juris Meija (pp. 3-3).

Euroanalysis XV, 2009: The European conference on analytical chemistry by Wolfgang Buchberger; Wolfgang Lindner (pp. 5-6).

is Head of the Institute of Analytical Chemistry at Johannes Kepler University, Linz. His main research interests are in the field of organic analytical sciences and organic trace analysis with applications in the areas of environmental analytical chemistry as well as method development for industrial chemistry including the characterization of polymeric materials. His current projects are mainly based on hyphenation of analytical high-performance separation techniques like chromatography and capillary electrophoresis with advanced and novel mass spectrometric detection tools. He is author and co-author of about 220 publications in scientific journals and of various chapters in textbooks on analytical separation techniques. Currently, he is a member of editorial boards of several analytical journals. He represents Austria in the Division of Analytical Chemistry within EuCheMS. holds the Chair in Analytical Chemistry at the University of Vienna and is head of the Research Group for Molecular Recognition Materials, Separation Sciences and Mass Spectrometry at the Institute of Analytical Chemistry. His research interests are manifold: inter alia he is known for his contributions to molecular recognition technologies in the context of separation of stereoisomers and enantiomers, analytically but also preparatively, which involves the synthesis of chiral selectors and novel materials; the development of highly selective materials for the separation and purification of proteins, e.g. monoclonal antibodies (IgGs) but also of other biopolymers; and the specific analysis of phosphorylated target analytes. His research group is also engaged in the application of diverse MS/MS technologies within the broad field of bioanalysis and pharmaceutical analysis. Prof. Lindner is author and co-author of more than 360 publications, has filed more than 15 international patents in various fields, serves on several editorial boards, has organized several symposia, has won distinguished awards, including the Chirality Medal and the A. J. P. Martin Gold Medal, and is active in national and international scientific societies.

E-learning in applied instrumental analysis: the example of cultural heritage preservation by Evangelia A. Varella (pp. 7-9).

Graduate studies in chemistry, pharmacy and pastoral theology; doctorate in natural sciences (Karl Ruprecht University of Heidelberg), doctorate in theology (Aristotle University of Thessaloniki); assistant professor at the chemistry department, Aristotle University of Thessaloniki). Secretary general of the International Academy for the History of Pharmacy; vice president of the administrative council of the European Chemistry Thematic Network Association; executive secretary of the Eurobachelor and Euromaster Label Committee, European Chemistry Thematic Network. Coordinator of the LLP virtual campus project on conservation science; coordinator of two MEDA TEMPUS projects for the implementation of master’s course studies on conservation science. Main scientific areas: history of experimental sciences; physicochemical characterization of organic materials of cultural interest.

Some people and places important in the history of analytical chemistry in Austria by D. Thorburn Burns (pp. 11-16).

Is Emeritus Professor of Analytical Chemistry at Queen’s University Belfast but remains active as a senior research fellow. His current research interests are in instrumental methods, data evaluation for legal and forensic purposes, and the history of analytical chemistry in Europe from the sixteenth to the nineteenth centuries. Among his honours and awards are the Ehren Nadel im Geld of the Analytical Institute of the Technical University of Vienna (1990) and the Fritz Pregl Medal of the Österreichische Gesellschaft für Analytische Chemie (1993).

The environmental challenge for analytical sciences by Manfred Grasserbauer (pp. 17-23).

Sustainable management of natural resources: air, water and soilClimate change and clean energyGlobal development cooperation Analytical sciences are required to provide policy-relevant information for the development and implementation of European Union legislation and form a strong pillar for a sustainable evolution of our region and our planet. It shows what information needs to be provided, how the necessary quality levels can be achieved and what new approaches, e.g. combining measurements and modelling, or earth observations with in situ chemical/physical measurements, need to be taken to achieve an integrated assessment of the state of the environment and to develop approaches for sustainable development.

Keywords: Analytical sciences; Environment; Sustainable development; Natural resources; Climate change; Renewable energies; Development cooperation

The principle of exhaustiveness versus the principle of parsimony: a new approach for the identification of biomarkers from proteomic spot volume datasets based on principal component analysis by Emilio Marengo; Elisa Robotti; Marco Bobba; Fabio Gosetti (pp. 25-41).

The field of biomarkers discovery is one of the leading research areas in proteomics. One of the most exploited approaches to this purpose consists of the identification of potential biomarkers from spot volume datasets produced by 2D gel electrophoresis. In this case, problems may arise due to the large number of spots present in each map and the small number of maps available for each class (control/pathological). Multivariate methods are therefore usually applied together with variable selection procedures, to provide a subset of potential candidates. The variable selection procedures available usually pursue the so-called principle of parsimony: the most parsimonious set of spots is selected, providing the best classification performances. This approach is not effective in proteomics since all potential biomarkers must be identified: not only the most discriminating spots, usually related to general responses to inflammatory events, but also the smallest differences and all redundant molecules, i.e. biomarkers showing similar behaviour. The principle of exhaustiveness should be pursued rather than parsimony. To solve this problem, a new ranking and classification method, “Ranking-PCA”, based on principal component analysis and variable selection in forward search, is proposed here for the exhaustive identification of all possible biomarkers. The method is successfully applied to three different proteomic datasets to prove its effectiveness. Figure A new ranking and classification method, Ranking-PCA, is presented for the identification of pools of potential biomarkers from electrophoretic spot volume datasets. The method represents a new perspective in biomarker identification since it searches for the most exhaustive set of potential candidates rather than the most parsimonious. In this way, all significant candidates can be effectively selected.

Keywords: Exhaustiveness; Biomarker discovery; Ranking PCA; Variable selection; 2D gel electrophoresis; Classification methods

Application of the novel 5-chloro-2,2,3,3,4,4,5,5-octafluoro-1-pentyl chloroformate derivatizing agent for the direct determination of highly polar water disinfection byproducts by Marco Vincenti; Francesca Fasano; Maria Carmen Valsania; Pierantonio Guarda; Susan D. Richardson (pp. 43-54).

A novel derivatizing agent, 5-chloro-2,2,3,3,4,4,5,5-octafluoropentyl chloroformate (ClOFPCF), was synthesized and tested as a reagent for direct water derivatization of highly polar and hydrophilic analytes. Its analytical performance satisfactorily compared to a perfluorinated chloroformate previously described, namely 2,2,3,3,4,4,5,5-octafluoropentyl chloroformate (OFPCF). The chemical properties (reactivity, selectivity, derivatization products, and their chromatographic and spectral features) for ClOFPCF were investigated using a set of 39 highly polar standard analytes, including, among others, hydroxylamine, malic and succinic acids, resorcinol, hydroxybenzaldehyde, and dihydroxybenzoic acid. Upon derivatization, the analytes were extracted from the aqueous solvent and analyzed by gas chromatography (GC)-mass spectrometry (MS) in the electron-capture negative ionization (ECNI) mode. Positive chemical ionization (PCI)-MS was used for confirming the molecular ions, which were virtually absent in the ECNI mass spectra. ClOFPCF showed good reaction efficiency, good chromatographic and spectroscopic properties (better than with OFPCF), good linearity in calibration curves, and low detection limits (0.3–1 µg/L). A unique feature of the derivatizations with ClOFPCF, and, in general, highly fluorinated chloroformates, is their effectiveness in reacting with carboxylic, hydroxylic, and aminic groups at once, forming multiply-substituted non-polar derivatives that can be easily extracted from the aqueous phase and determined by GC-ECNI-MS. The entire procedure from raw aqueous sample to ready-to-inject hexane solution of the derivatives requires less than 10 min. Another benefit of this procedure is that it produced stable derivatives, with optimal volatility for GC separation, and high electron affinity, which allows their detection as negative ions at trace level. In addition, their mass spectra exhibits chlorine isotopic patterns that clearly indicate how many polar hydrogens of the analyte undergo derivatization. Finally, derivatization with ClOFPCF was used successfully to identify 13 unknown highly polar disinfection byproducts (DBPs) in ozonated fulvic and humic acid aqueous solutions and in real ozonated drinking water. Figure The derivatization of hydroxylamine with 5-chloro-2,2,3,3,4,4,5,5-octafluoropentyl chloroformate yields optimal gas chromatographic separation despite a 27-fold molecular weight increment.

Keywords: Humic substances; Water disinfection byproducts; Derivatization; Chloroformate; Hydrophilic compounds; ECNI

An immunochemical test for rapid screening of zearalenone and T-2 toxin by Evgenia Yu. Basova; Irina Yu. Goryacheva; Tatiana Yu. Rusanova; Natalia A. Burmistrova; Richard Dietrich; Erwin Märtlbauer; Christ’l Detavernier; Carlos Van Peteghem; Sarah De Saeger (pp. 55-62).

An immunochemically based test for non-instrumental simultaneous detection of zearalenone (ZEA) and T-2 toxin (T2) in feed was developed. The method combines clean-up of sample extract, pre-concentration of analytes by immunoextraction and immunodetection through the enzymatic reaction of horseradish peroxidase (HRP). The test is housed inside a standard 1-mL solid-phase extraction column and consists of three layers: two test layers (one for ZEA and another for T2) with immobilised specific antibodies and one control layer with bound anti-HRP antibodies. Feed extract was passed through an additional column with clean-up layer, which was disconnected after extract application. Total assay time was about 15 min for six samples and detection time was 4 min after chromogenic substrate application. Under optimised conditions a cut-off level for ZEA and T2 of 100 µg/kg was established. Different feed types were analysed for ZEA and T2 contamination by the proposed method and results were confirmed by LC-MS/MS. Figure An immunochemically-based test for non-instrumental simultaneous detection of zearalenone (ZEA) and T-2 toxin (T2) in feed.

Keywords: Non-instrumental test; Visual detection; Fusarium toxin; Mycotoxin; Zearalenone; T-2 toxin; Feed

Direct chiral determination of free amino acid enantiomers by two-dimensional liquid chromatography: application to control transformations in E-beam irradiated foodstuffs by Vanesa Guillén-Casla; María Eugenia León-González; Luis Vicente Pérez-Arribas; Luis María Polo-Díez (pp. 63-75).

Changes in free amino acids content and its potential racemization in ready-to-eat foods treated with E-beam irradiation between 1 and 8 kGy for sanitation purposes were studied. A simple heart cut two-dimensional high performance liquid chromatographic method (LC–LC) for the simultaneous enantiomeric determination of three pairs of amino acids used as markers (tyrosine, phenylalanine, and tryptophan) is presented. The proposed method involves the use of two chromatographs in an LC–LC achiral–chiral coupling. Amino acids and their decomposition products were firstly separated in a primary column (C₁₈) using a mixture of ammonium acetate buffer (20 mM, pH 6) (94%) and methanol (6%) as the mobile phase. Then, a portion of each peak was transferred by heart cutting through a switching valve to a teicoplanin-chiral column. Methanol (90%)/water (10%) was used as the mobile phase. Ultraviolet detection was at 260 nm. Detection limits were between 0.16 and 3 mg L⁻¹ for each enantiomer. Recoveries were in the range 79–98%. The LC–LC method combined with the proposed sample extraction procedure is suitable for complex samples; it involves an online cleanup, and it prevents degradation of protein, racemization of L-enantiomers, and degradation of tryptophan. Under these conditions, D-amino acids were not found in any of the analyzed samples at detection levels of the proposed method. Figure Two-dimensional direct chiral liquid chromatograms of tyrosine, phenilalanine and tryptophan

Keywords: Amino acids/peptides; Chiral analysis; Foods/beverages; HPLC; Multidimensional liquid chromatography; Column switching

Exploiting automatic on-line renewable molecularly imprinted solid-phase extraction in lab-on-valve format as front end to liquid chromatography: application to the determination of riboflavin in foodstuffs by Hugo M. Oliveira; Marcela A. Segundo; José L. F. C. Lima; Manuel Miró; Victor Cerdà (pp. 77-86).

In the present work, it is proposed, for the first time, an on-line automatic renewable molecularly imprinted solid-phase extraction (MISPE) protocol for sample preparation prior to liquid chromatographic analysis. The automatic microscale procedure was based on the bead injection (BI) concept under the lab-on-valve (LOV) format, using a multisyringe burette as propulsion unit for handling solutions and suspensions. A high precision on handling the suspensions containing irregularly shaped molecularly imprinted polymer (MIP) particles was attained, enabling the use of commercial MIP as renewable sorbent. The features of the proposed BI-LOV manifold also allowed a strict control of the different steps within the extraction protocol, which are essential for promoting selective interactions in the cavities of the MIP. By using this on-line method, it was possible to extract and quantify riboflavin from different foodstuff samples in the range between 0.450 and 5.00 mg L⁻¹ after processing 1,000 µL of sample (infant milk, pig liver extract, and energy drink) without any prior treatment. For milk samples, LOD and LOQ values were 0.05 and 0.17 mg L⁻¹, respectively. The method was successfully applied to the analysis of two certified reference materials (NIST 1846 and BCR 487) with high precision (RSD < 5.5%). Considering the downscale and simplification of the sample preparation protocol and the simultaneous performance of extraction and chromatographic assays, a cost-effective and enhanced throughput (six determinations per hour) methodology for determination of riboflavin in foodstuff samples is deployed here. Figure Schematic representation of the manifold for determination of riboflavin in foodstuff. LOV lab-on-valve, MS multisyringe, HPLC high-performance liquid chromatography, Si syringe, Vi three-way commutation valve ( position off, solid line position on), A air, CS conditioning solvent (50% (v/v) MeOH/H2O), BS bead suspension in conditioning solvent, C carrier solution (H2O), D diluent (H2O), W waste, CC central channel, EL eluent (50% (v/v) MeOH/H2O+1% (v/v) CH3COOH), B channel for bead discarding, Sa sample/standard solution, HC holding coil, L1 connection tubing (8 cm), L2 connection tubing (44 cm), P chromatographic pump, IV injection valve, MC monolithic chromatographic column, λ diode array detector

Keywords: Solid-phase extraction; Molecularly imprinted polymer; Flow analysis; Lab-on-valve; Riboflavin; Foodstuff

Determination of aflatoxin B₁ in alcoholic beverages: comparison of one- and two-photon-induced fluorescence by Claudia Rasch; Maike Böttcher; Michael Kumke (pp. 87-92).

The qualitative and quantitative analysis of aflatoxin B₁ in a model system (water/ethanol), in different wines and in beer using one- and two-photon-induced fluorescence is discussed. The absorption and fluorescence properties of aflatoxin B₁ depend on the solvent and pH. The two-photon-absorption cross-section was calculated for aflatoxin B₁ in beer and wine (σ ₂ ∼ 25 GM) for excitation at 720 nm. A comparison of the one- and two-photon- induced fluorescence results showed that the disturbance due to background emission originating from matrix constituents is significantly reduced under two-photon-excitation conditions. The limit of detection for the one- and two-photon-induced fluorescence was determined.

Keywords: Aflatoxin B₁ ; Fluorescence; Two-photon absorption; Two-photon-absorption cross-section; Beer; Wine

Development and validation of a LC–MS/MS method for the simultaneous determination of aflatoxins, dyes and pesticides in spices by C. Ferrer Amate; H. Unterluggauer; R. J. Fischer; A. R. Fernández-Alba; S. Masselter (pp. 93-107).

Based on several alerts from European countries over the last years concerning spices, we have been encouraged to establish an accurate method for the determination of dyes, aflatoxins and pesticides in various types of spices using reversed-phase (RP) liquid chromatography–tandem mass spectrometry interfaced with electrospray (LC–ESI–MS/MS). A simple sample treatment procedure entailing the use of an extraction step with acetonitrile without further cleanup has been developed. A C18 column with an aqueous ammonium formate/methanol mixture as the mobile phase was used, and gradient elution was performed. Mass spectral acquisition was done in positive ion mode by applying multiple reaction monitoring of at least two fragmentation transitions per compound to provide a high degree of selectivity. The method was in-house validated in terms of linearity, sensitivity, repeatability, recovery and selectivity on six kinds of spices. Satisfactory results in the majority of the cases were obtained for all analytes and matrices, with practical limits of quantitation acceptable for routine monitoring purposes. Extraction recoveries for most of the compounds ranged from 60% to 140% at spiking levels of 0.05 and 0.5 mg kg⁻¹. The applicability of the method for the simultaneous determination of dyes, aflatoxins and pesticides in several types of spices was demonstrated, and the method successfully applied to a limited number of products from the local market.

Keywords: LC–MS/MS; Food analysis; Spices; Pesticides; Dyes; Aflatoxins; Validation study

Fluctuation in the ergosterol and deoxynivalenol content in barley and malt during malting process by Vlastimil Dohnal; Alena Jezkova; Lucie Pavlikova; Kamil Musilek; Daniel Jun; Kamil Kuca (pp. 109-114).

This paper describes determination of the deoxynivalenol and ergosterol in samples from different varieties of barley and, consequently, malt produced from this barley. In total, 20 samples of barley and 20 samples of barley malt were analyzed. The alkaline hydrolysis with consequent extraction into hexane was applied to obtain the ergosterol from cereals. Extraction to acetonitrile/water and subsequent solid-phase extraction (SPE) were used for deoxynivalenol. The determination of the samples was performed on high-performance liquid chromatography using UV detection (ergosterol) and mass spectrometric detection (deoxynivalenol). The influence of the malting process on the production of two compounds of interest was assessed from obtained results. Ergosterol concentration ranged 0.88–15.87 mg/kg in barley and 2.63–34.96 mg/kg in malt, where its content increased to 95% compared to samples before malting. The malting process was observed as having a significant effect on ergosterol concentration (P = 0.07). The maximum concentration of deoxynivalenol was found to be 641 µg/kg in barley and 499 µg/kg in malt. Its concentration was lower than the legislative limit for unprocessed cereals (1,250 µg/kg). The statistic effect of the malting process on deoxynivalenol production was not found. Linear correlation between ergosterol and deoxynivalenol content was found to be very low (barley R = 0.02, malt R = 0.01). The results revealed that it is not possible to consider the ergosterol content as the indicator of deoxynivalenol contamination of naturally molded samples.

Keywords: Ergosterol; Deoxynivalenol; Barley; Malt; Mold

Comparison of two derivatization-based methods for solid-phase microextraction–gas chromatography–mass spectrometric determination of bisphenol A, bisphenol S and biphenol migrated from food cans by P. Viñas; N. Campillo; N. Martínez-Castillo; M. Hernández-Córdoba (pp. 115-125).

An environmentally friendly sample pretreatment system based on solid-phase microextraction (SPME) for the sensitive determination of bisphenol A (BPA), bisphenol S (BPS) and biphenol (BP) is described. Two derivatisation reactions to obtain volatile derivatives are compared. Derivatisation with acetic anhydride (AA) was performed in situ in a 5-mM Na₂CO₃/NaHCO₃ buffer solution and analytes were extracted by direct immersion (DI) using a PA fibre (85 µm) at 90°C for 40 min with stirring at 1,500 rpm. For derivatisation with bis-(trimethylsilyl)trifluoroacetamide (BSTFA), the analytes were first extracted by DI using the PA fibre at 70°C for 40 min with stirring at 500 rpm. The fibre was then removed, dried in a nitrogen stream for 2 min and introduced into the headspace of BSTFA at 50°C for 30 s. After derivatisation, the analytes were desorbed in the injection port of the GC in the splitless mode at 280°C for 4 min. The separation was carried out by coupling gas chromatography with mass spectrometry in the selected ion monitoring mode, GC-MS(SIM). The method allowed the determination of the migrating levels of bisphenols found in food cans, and it was validated for linearity, detection and quantitation limits, selectivity, accuracy and precision. Detection limits ranged from 3 to 16 pg mL⁻¹, depending on the compound, at a signal-to-noise ratio of 3. Recoveries obtained for spiked samples were satisfactory for all compounds. Levels of BPA were higher than those of BPS and the lowest contents were found for BP. Figure The amounts of bisphenols migrated from food cans are very low

Keywords: Gas chromatography–mass spectrometry; Solid-phase microextraction; On-fibre derivatisation; Bisphenols; Food cans

Validated HPAEC-PAD method for prebiotics determination in synbiotic fermented milks during shelf life by Chiara Borromei; Antonella Cavazza; Claudio Corradini; Claudia Vatteroni; Adelina Bazzini; Raffaella Ferrari; Paolo Merusi (pp. 127-135).

Interest concerning functional food has been growing in recent years, and much attention has been focused on the choice of prebiotic fibers and probiotic microorganisms added to food products with the aim of improving health, producing synbiotic products. In the work reported here, an innovative analytical method performed by high-performance anion-exchange chromatography (HPAEC) with pulsed electrochemical detection has been optimized and validated for application to the study of prebiotic effects in synbiotic fermented milk prepared by addition of probiotics. The proposed method permits the evaluation of fructooligosaccharides and inulooligosaccharides with degrees of polymerization of 6–7 and 4–7, respectively. Quantitative determination was performed on oligosaccharides, whose standards are not commercially available, by employing calibration curves built by adding a known amount of the fiber used as an ingredient to the matrix. The work provides results from a parallel study on simultaneous variations of prebiotics and probiotics during the shelf life of fermented milk samples. The main advantage over time-consuming, classic enzymatic methods, whose results are limited only to average fiber content, is the possibility of dosing each carbohydrate by performing a single HPAEC run. Validation in terms of detection and quantitation limits, linearity, precision, and recovery was carried out.

Keywords: High-performance anion-exchange chromatography with pulsed electrochemical detection; Fructooligosaccharides; Inulooligosaccharides; Probiotics; Synbiotics; Fermented milks; Validation

Identification of a new co-crystal of salicylic acid and benzamide of pharmaceutical relevance by M. A. Elbagerma; H. G. M. Edwards; T. Munshi; I. J. Scowen (pp. 137-146).

Raman spectroscopy, X-ray powder diffraction/X-ray crystallography and differential scanning calorimetry have been used to study the phenomenon of co-crystal formation in stoichiometric mixtures of salicylic acid with benzamide. Raman spectroscopy was particularly useful for the characterization of the products and was used to determine the nature of the interactions in the co-crystals. It was observed that little change in the vibrational modes associated with the phenyl groups of the respective reactants took place upon co-crystal formation, but changes in intensities of the vibrational modes associated with the amide and the carboxylic acid groups were observed upon co-crystal formation. Several new vibrational bands were identified in the co-crystal which were not manifested in the physical mixture of both components and could be used as diagnostic features of co-crystal formation.

Keywords: Co-crystals; Raman spectroscopy; DSC; Salicylic acid; Benzamide; Hydrogen bonding

Quantitative LC-ESI-MS/MS metabolic profiling method for fatty acids and lipophilic metabolites in fermentation broths from β-lactam antibiotics production by Simone Schiesel; Michael Lämmerhofer; Wolfgang Lindner (pp. 147-160).

In the present paper, we report on the development of a straightforward reversed-phase liquid chromatography–electrospray ionization–tandem mass spectrometry method for the determination of the most abundant fatty acids; α-tocopherol and cephalosporin P1 in fermentation broths. Using this method, fatty acids could be successfully determined in extracts of fermentation broths from penicillin and cephalosporin production without prior derivatization. Matrix effects were investigated in detail, and various kinds of calibrations (i.e., by use of neat standard solutions as well as by matrix-matched calibration employing standard addition each with and without internal standards) were comparatively assessed. The optimized and validated method was employed for the analysis of extracts of fermentation broths and nutrition media.

Keywords: Fatty acids; α-Tocopherol; β-Lactam antibiotics; Penicillin; HPLC-ESI-MS/MS; Metabolic profiling

Development of an LC–MS/MS method for analysis of interconvertible Z/E isomers of the novel anticancer agent, Bp4eT by Ján Stariat; Petra Kovaříková; Jiří Klimeš; Danuta S. Kalinowski; Des R. Richardson (pp. 161-171).

This study was focused on a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method development for quantification of a novel potential anticancer agent, 2-benzoylpyridine 4-ethyl-3-thiosemicarbazone (Bp4eT), in aqueous media. Solid Bp4eT was found to consist predominantly of the Z isomer, while in aqueous media, both isomers coexist. Sufficient separation of both isomers was achieved on a Synergi 4u Polar RP column with a mobile phase composed of 2 mM ammonium formate, acetonitrile, and methanol (30:63:7; v/v/v). The photo diode array analysis of both isomers demonstrated different absorption spectra which hindered UV-based quantification. However, an equal and reproducible response was found for both isomers using an MS detector, which enables the determination of the total content of Bp4eT (i.e., both E− and Z− isomeric forms) by summation of the peak areas of both isomers. 2-Hydroxy-1-naphthylaldehyde 4-methyl-3-thiosemicarbazone (N4mT) was selected as the internal standard. Quantification was performed in selective reaction monitoring using the main fragments of [M+H]⁺ (240 m/z for Bp4eT and 229 m/z for N4mT). The method was validated over 20–600 ng/ml. This procedure was applied to a preformulation study to determine the proper vehicle for parenteral administration. It was found that Bp4eT was poorly soluble in aqueous media. However, the solubility can be effectively improved using pharmaceutical cosolvents. In fact, a 1:1 mixture of PEG 300/0.14 M saline markedly increased solubility and may be a useful drug formulation for intravenous administration. This investigation further accelerates development of novel anticancer thiosemicarbazones. The described methods will be useful for analogs currently under development and suffering the same analytical issue. Figure Chromatogram of the LC-MS/MS analysis of Bp4eT; UV absorption spectra of both Bp4eT isomers.

Keywords: 2-Benzoylpyridine 4-ethyl-3-thiosemicarbazone; Bp4eT; LC–MS; Isomer; Solubility

Determination of adrenolytic drugs by SPME–LC–MS by Boguslaw Buszewski; Pawel Olszowy; Tomasz Ligor; Malgorzata Szultka; Jacek Nowaczyk; Maciej Jaworski; Marek Jackowski (pp. 173-179).

Five adrenolytic drugs have been analyzed by liquid chromatography–mass spectrometry (LC–MS). Samples were prepared by solid-phase microextraction (SPME) using polypyrrole fibers coated on stainless steel support as an adsorbent for the drugs. Adsorption efficiencies were 95% and were close for all the drugs investigated. Relative standard deviations (RSD), calculated for samples prepared in standard solutions, were in the range 2.5–13%, however RSD values for the drugs in human plasma were 2.5–4.5%. Using LC–MS the limit of detection (LOD) and the limit of quantification (LOQ) were in the ranges 0.11–0.18 and 0.39–0.54 ng mL⁻¹, respectively, for the five drugs.

Keywords: Adrenolytic drugs; Solid-phase microextraction; High-performance liquid chromatography; Mass spectrometry

Quantification of chlorpheniramine maleate enantiomers by ultraviolet spectroscopy and chemometric methods by P. Valderrama; A. L. Romero; P. M. Imamura; I. R. S. Magalhães; P. S. Bonato; R. J. Poppi (pp. 181-188).

Chlorpheniramine maleate (CLOR) enantiomers were quantified by ultraviolet spectroscopy and partial least squares regression. The CLOR enantiomers were prepared as inclusion complexes with β-cyclodextrin and 1-butanol with mole fractions in the range from 50 to 100%. For the multivariate calibration the outliers were detected and excluded and variable selection was performed by interval partial least squares and a genetic algorithm. Figures of merit showed results for accuracy of 3.63 and 2.83% (S)-CLOR for root mean square errors of calibration and prediction, respectively. The ellipse confidence region included the point for the intercept and the slope of 1 and 0, respectively. Precision and analytical sensitivity were 0.57 and 0.50% (S)-CLOR, respectively. The sensitivity, selectivity, adjustment, and signal-to-noise ratio were also determined. The model was validated by a paired t test with the results obtained by high-performance liquid chromatography proposed by the European pharmacopoeia and circular dichroism spectroscopy. The results showed there was no significant difference between the methods at the 95% confidence level, indicating that the proposed method can be used as an alternative to standard procedures for chiral analysis.

Keywords: Chlorpheniramine maleate; Enantiomers; Ultraviolet spectroscopy; Multivariate calibration; Validation

Electrochemical evaluation and determination of antiretroviral drug fosamprenavir using boron-doped diamond and glassy carbon electrodes by Mehmet Gumustas; Sibel A. Ozkan (pp. 189-203).

Fosamprenavir is a pro-drug of the antiretroviral protease inhibitor amprenavir and is oxidizable at solid electrodes. The anodic oxidation behavior of fosamprenavir was investigated using cyclic and linear sweep voltammetry at boron-doped diamond and glassy carbon electrodes. In cyclic voltammetry, depending on pH values, fosamprenavir showed one sharp irreversible oxidation peak or wave depending on the working electrode. The mechanism of the oxidation process was discussed. The voltammetric study of some model compounds allowed elucidation of the possible oxidation mechanism of fosamprenavir. The aim of this study was to determine fosamprenavir levels in pharmaceutical formulations and biological samples by means of electrochemical methods. Using the sharp oxidation response, two voltammetric methods were described for the determination of fosamprenavir by differential pulse and square-wave voltammetry at the boron-doped diamond and glassy carbon electrodes. These two voltammetric techniques are 0.1 M H₂SO₄ and phosphate buffer at pH 2.0 which allow quantitation over a 4 × 10⁻⁶ to 8 × 10⁻⁵ M range using boron-doped diamond and a 1 × 10⁻⁵ to 1 × 10⁻⁴ M range using glassy carbon electrodes, respectively, in supporting electrolyte. All necessary validation parameters were investigated and calculated. These methods were successfully applied for the analysis of fosamprenavir pharmaceutical dosage forms, human serum and urine samples. The standard addition method was used in biological media using boron-doped diamond electrode. No electroactive interferences from the tablet excipients or endogenous substances from biological material were found. The results were statistically compared with those obtained through an established HPLC-UV technique; no significant differences were found between the voltammetric and HPLC methods.

Keywords: Fosamprenavir; Oxidation mechanism; Glassy carbon; Boron-doped diamond; Determination; Voltammetry

Determination of insoluble avian eggshell matrix proteins by Ivan Mikšík; Pavla Sedláková; Katerina Lacinová; Statis Pataridis; Adam Eckhardt (pp. 205-214).

The organic components of bones and other mineralized tissues have a high impact on the organization and deposition of calcium, and consequently influence the mechanical properties of those tissues. The extractable proteins of avian eggshells have been studied extensively and many of them have been identified; insoluble (non-extractable) proteins have been sparsely studied, however. In the work discussed in this paper we studied EDTA-insoluble proteins by gradual decalcification of eggshell with EDTA. The insoluble proteinaceous films were chemically treated with cyanogen bromide and the mixtures of large fragments obtained were gradually precipitated with salt. The separated fractions were digested with trypsin and analyzed by HPLC–MS–MS (ion trap mass spectrometer). Analysis of the entire eggshell matrix (without precipitation steps) only enabled 6 proteins to be determined (ovocalyxins 32 and 36, ovocleidin 17 and 116, clusterin, and ovalbumin). Pretreatment of the individual eggshell layers and gradual precipitation with salt markedly increased the number of proteins identified – 28 proteins were determined. We identified for the first time collagens I (two chains) and III in the eggshell matrix, and Kunitz-like protease inhibitor as a major shell matrix protein. Besides the above mentioned proteins we can also mention EDIL3, fibronectin, sulfhydryl oxidase, tubulin alpha 1, lysozyme, Dickkopf-related protein 3, keratins, and ovotransferrin. The relative abundances of proteins in all eggshell layers were determined using the exponentially modified protein abundance index (emPAI). In the cuticle layer seven proteins were identified, whereas 16 proteins were described in the palisade layer and 23 in the mammillary layer.

Keywords: Biological samples; Eggshell; Insoluble proteins; Matrix proteins; Chicken proteins

Raman spectroscopic analysis of minerals and organic molecules of relevance to astrobiology by A. I. Alajtal; H. G. M. Edwards; I. J. Scowen (pp. 215-221).

Characteristic geological features and hydrated minerals recently found on the surface of Mars by the NASA planetary rovers Spirit and Opportunity suggest that a possible biosphere could have once existed there. Analytical instrumentation protocols for the unequivocal detection of biomarkers in suitable geological matrices are critical for future unmanned explorations, including the forthcoming ESA-ExoMars mission scheduled for 2018. Raman spectroscopy is currently a part of the Pasteur instrumentation suite of the ExoMars mission scheduled for 2018 for the remote detection of extant or extinct life signatures in the Martian surface and subsurface. Terrestrial analogues of Martian sites have been identified, and the biogeological modifications incurred as a result of extremophilic survival activity have been studied. Polyaromatic hydrocarbons (PAHs) are recognised as a class of degradation product that occur from biological processes terrestrially. In this work, various concentrations of polyaromatic hydrocarbons in matrices of gypsum, calcite and quartz have been investigated by Raman microspectrometry to determine the lowest detectable organic levels. The studies are conceived in simulation of their potential PAHs identification in geobiological conditions in Martian scenarios. Two laser source wavelengths, namely, 785 and 633 nm, were adopted to excite Raman spectra from the PAHs, which represent degraded carbons and therefore potentially provide a key bimolecular marker of ancient life.

Keywords: Raman spectroscopy; Mars analogue; Minerals; PAHs

Determination of heterocyclic amines in urine samples by capillary liquid chromatography with evaporated light-scattering detection by Fernando De Andrés; Mohammed Zougagh; Gregorio Castañeda; Angel Ríos (pp. 223-231).

A rapid and simple method for separation and detection of six heterocyclic aromatic amines (2-amino-1-methyl-6-phenylimidazo [4,5-b]-pyridine, 2-amino-1-methyl-imidazo [4,5-f]-quinoline, 2-amino-3,8-dimethyl-imidazo [4,5-f]-quinoxaline, 2-amino-3,7,8-trimethyl-imidazo [4,5-f]-quinoxaline, 2-amino-3,4,8-trimethyl-imidazo [4,5-f]-quinoxaline, and 2-amino-3,4-dimethyl-imidazo [4,5-f]-quinoline) in human urine samples is proposed to reflect daily intake and recent HAAs exposure. This method comprises previous clean-up and preconcentration of the analytes on Strata-X reversed phase extraction cartridges followed by capillary liquid chromatography (CLC) and evaporative light-scattering detection (ELSD). A mobile phase of acetonitrile and ammonium acetate 35 mM at pH 5.15 through a gradient of composition and a flow rate of 15 μL min⁻¹ resulted in good separations of the analytes. Temperature and gas pressure were optimized for detection. The CLC-ELSD allows the separation and quantification of HAAs with good resolution, precision, and sensitivity. The usefulness of the proposed method was demonstrated by the analysis of synthetic and natural human urine samples spiked with different concentration levels of heterocyclic amines.

Keywords: Capillary liquid chromatography–evaporative light-scattering detection; Strata-X cartridges; Heterocyclic aromatic amines; Human urine samples

Voltammetric detection of damage to DNA caused by nitro derivatives of fluorene using an electrochemical DNA biosensor by Vlastimil Vyskočil; Ján Labuda; Jiří Barek (pp. 233-241).

An electrochemical DNA biosensor based on the screen printed carbon paste electrode (SPCPE) with an immobilized layer of calf thymus double-stranded DNA has been used for in vitro investigation of the interaction between genotoxic nitro derivatives of fluorene (namely 2-nitrofluorene and 2,7-dinitrofluorene) and DNA. Two types of DNA damage have been detected at the DNA/SPCPE biosensor: first, that caused by direct association of the nitrofluorenes, for which an intercalation association has been found using the known DNA intercalators [Cu(phen)₂]²⁺ and [Co(phen)₃]³⁺ as competing agents, and, second, that caused by short-lived radicals generated by electrochemical reduction of the nitro group (observable under specific conditions only). Figure Anodic DPV response of DNA bases at the DNA/SPCPE (after baseline correction) recorded in AcB -methanol (99:1) medium; Eamp 50 mV, pulse width 100 ms, scan rate 20 mV s−1, Estep 5 mV, 36°C. DP voltammograms recorded at the DNA/SPCPE before (green curve) and after successive CV cathodic/anodic cycling between 0 and −1000 mV (15 scans; scan rate 50 mV s−1) in solution of 2-NF (c=1×10−5 mol L−1) in AcB -methanol (99:1) (red curve). Two different DNA/SPCPEs were used to record green and red curve

Keywords: 2-Nitrofluorene; 2,7-Dinitrofluorene; DNA biosensor; Screen printed carbon paste electrode; Electrochemical detection; DNA damage

Simultaneous determination by ultra-performance liquid chromatography–atmospheric pressure chemical ionization time-of-flight mass spectrometry of nitrated and oxygenated PAHs found in air and soot particles by Giovanni Mirivel; Véronique Riffault; Jean-Claude Galloo (pp. 243-256).

An ultra-performance liquid chromatographic-atmospheric pressure chemical ionization time-of-flight mass spectrometric (UPLC-APCIToFMS) method for rapid analysis of twelve nitrated polycyclic aromatic hydrocarbons (NPAHs) and nine oxygenated polycyclic aromatic hydrocarbons (OPAHs) in particle samples has been developed. The extraction step using pressurized liquid extraction was optimized by experimental design methods and the concentrated extracts were analyzed without further clean-up. Matrix effects resulting in suppression or enhancement of the response during the ionization step were not observed. The suitability of the developed method is demonstrated by analysis of six different particle samples including standard reference materials, atmospheric particles collected by a high-volume sampler at an urban background site, and a soot sample from a burner. Results from these measurements showed clear differences between the different kinds of samples. Concentrations from reference materials are in good agreement with those from previous studies. Additionally a clear seasonal trend could be observed in atmospheric NPAH and OPAH concentrations found in real samples, with higher concentrations in winter.

Keywords: Nitrated polycyclic aromatic hydrocarbons; Oxygenated polycyclic aromatic hydrocarbons; Experimental design; Ultra-high-performance liquid chromatography (UPLC); Time-of-flight mass spectrometry (ToFMS); Standard reference materials (SRM)

Determination of brominated diphenyl ethers (from mono- to hexa- congeners) in indoor dust by pressurised liquid extraction with in-cell clean-up and gas chromatography–mass spectrometry by María Pilar Martínez; José David Carrillo; María Teresa Tena (pp. 257-267).

This study presents a selective pressurised liquid extraction (PLE) and gas chromatography–mass spectrometry/mass spectrometry method for the determination of brominated diphenyl ethers (BDEs) in indoor dust. Selective PLE consisted of the addition of Florisil mixed with the sample in order to perform an in-cell clean-up. This approach provided a cleaner and almost colourless extract, ready to be injected in the gas chromatograph. The PLE conditions were studied using an experimental design, firstly a 4 × 3 × 2 multifactor categorical design to screen sorbent, solvent and temperature and then a central composite design to optimise sorbent mass, temperature and time. Finally, the number of extraction cycles was studied. The selected conditions were 4 g of Florisil all mixed with the sample and no additional clean-up sorbent layer, 1:1 n-hexane-dichloromethane, 60% flush volume, 40 °C, 1,500 psi, 2-min static time and one cycle. The proposed method allowed accurate determination of BDEs, with recovery values between 82% and 101% and detection limits between 0.06 and 0.24 ng g⁻¹. It also has advantages over other existing methods in terms of simplicity, automation, analysis time and solvent consumption.

Keywords: Brominated diphenyl ethers; Indoor dust; Pressurised liquid extraction; Gas chromatography; Mass spectrometry; In-cell clean-up

Determination of organic UV filters in water by stir bar sorptive extraction and direct analysis in real-time mass spectrometry by Manuela Haunschmidt; Christian W. Klampfl; Wolfgang Buchberger; Robert Hertsens (pp. 269-275).

A screening method for analyzing environmental waters contaminated with UV filters using direct analysis in real-time mass spectrometry (DART-MS) was developed. To demonstrate the suitability of DART-MS a test set of seven organic UV filters, namely benzophenone-3 (BP-3), ethylhexyl dimethyl p-aminobenzoate (OD-PABA), 4-t-butyl-4′-methoxydibenzoylmethane (BM-DBM), homomethyl salicylate (HMS), 2-(ethylhexyl) salicylate (EHS), octocrylene (OC), and 4-methylbenzylidene camphor (4-MBC), was defined. In the first step, standard solutions of the analytes prepared in methanol were investigated in order to determine optimum parameters for the DART-MS. Because of the very low concentrations of UV filters expected in environmental water samples, a pre-concentration step using stir bar sorptive extraction was performed. DART-MS allows the direct, simple and rapid semi-quantitative analysis of the analytes enriched on the surface of the polydimethylsiloxane-coated stir bars. The optimized method provided calibration curves with correlation coefficients R > 0.959, repeatability from 5% (for 4-MBC) to 30% (for BM-DBM) relative standard deviation and limits of detection lower than 40 ng L⁻¹ for all analytes. Finally, real lake water samples from locations with typical leisure activities were analyzed. Results obtained with the developed DART-MS method were cross-checked by confirmatory analysis using thermodesorption gas chromatography mass spectrometry (TD-GC-MS). Thereby, it could be demonstrated that both analytical methods provide comparable concentrations for the UV filters in the lake water samples. Figure DART-MS measurement of UV filters enriched by stir bar sorptive extraction.

Keywords: Eusolex; Sunscreen agents; Water analysis; DART mass spectrometry

Method for the simultaneous determination of the most problematic families of organic pollutants in compost and compost-amended soil by M. M. González; J. L. Santos; I. Aparicio; E. Alonso (pp. 277-285).

Linear alkylbenzene sulfonates (LAS), nonylphenol ethoxylates (NPE; sum of nonylphenol, nonylphenol monoethoxylate, and nonylphenol diethoxylate), and di-(2-ethylhexyl)phthalate (DEHP) are the most problematic organic pollutants in sludge owing to their high concentrations and the concentration limits of 2,600, 50, and 100 mg/kg, respectively, proposed in the European Union directive draft for land application of sludge. In this paper, an analytical method for the simultaneous determination of the C₁₀, C₁₁, C₁₂, and C₁₃ LAS homologues, the nonylphenolic compounds nonylphenol, nonylphenol monoethoxylate, and nonylphenol diethoxylate, and di(2-ethylhexyl)phthalate in compost and compost-amended soil is proposed. The method is based on sonication-assisted extraction, cleanup by solid-phase extraction, and determination by high-performance liquid chromatography with diode-array and fluorescence detectors. The mean recoveries of LAS, NPE, and DEHP were 83, 87, and 79%, respectively, in compost samples, and 77, 96, and 99%, respectively, in compost-amended soil samples. The limits of detection and quantification in compost samples were lower than 6.77 and 22.3 mg/kg dry matter, respectively, for LAS; lower than 7.34 and 22.8 mg/kg dry matter, respectively, for NPE; and 0.78 and 1.18 mg/kg dry matter, respectively, for DEHP. The limits of detection and quantification in compost-amended soil samples were lower than 0.03 and 0.10 mg/kg dry matter, respectively, for LAS; lower than 0.04 and 0.12 mg/kg dry matter, respectively, for NPE; and 0.03 and 0.10 mg/kg dry matter, respectively, for DEHP. The method was successfully applied to compost and compost-amended soil samples from Seville (south of Spain). Figure Sampling in a compost pile

Keywords: Linear alkylbenzene sulfonates; Nonylphenol ethoxylates; Di(2-ethylhexyl)phthalate; Compost; Compost-amended soil

Holistic visualisation of the multimodal transport and fate of twelve pharmaceuticals in biosolid enriched topsoils by Leon Barron; Ekaterina Nesterenko; Kris Hart; Emma Power; Brian Quinn; Brian Kelleher; Brett Paull (pp. 287-296).

The use of municipal biosolids as agricultural fertilisers has raised significant concerns in recent years. As part of this, the presence of complex mixtures of pharmaceutical residues and their effects on soil ecosystems remains particularly under-researched. This study focuses on the transfer of a selection of pharmaceutical residues from municipal sewage sludge to agricultural topsoils and their fate therein after an accelerated 6-month rainfall event. Twelve pharmaceuticals encompassing antibiotics, analgesics, anti-inflammatories, beta-blockers, hyperlipidaemics and stimulants were invesigated by employing a combination of extraction techniques and liquid chromatography-tandem mass spectrometry. Both liquid- and solid-phase pharmaceutical contents were analysed and pharmaceutical and personal care products quantified at defined timepoints to elucidate transport behaviour and transformation potential. Results show the distribution and separation of pharmaceuticals over a 100-mm soil depth following typical biosolid enrichment. Using experimentally determined solid–water partition coefficients (K _d) and hydrophobicity distribution ratios (D _ow), mobility and modes of interaction under dynamic conditions are discussed. Finally, a brief study into the susceptibility of soil microbes is also presented. To our knowledge, this is the first investigation of pharmaceutical and personal care products release from amended biosolids to soils to include the factors and mechanisms governing their distribution and transformation even over relatively shallow depths. It applies multicompartmental and mass-balanced chemical analyses as well as microbiological approaches for a holistic view of these complex processes. Figure Transport behaviour and fate of pharmaceuticals in biosolid enriched topsoils

Keywords: Soil; Sludge; Transport; Transformation; Pharmaceuticals

Capillary liquid chromatography with off-line mid-IR and Raman micro-spectroscopic detection: analysis of chlorinated pesticides at ppb levels by Sergio Armenta; Bernhard Lendl (pp. 297-308).

A flow-through microdispenser was used as a solvent elimination interface, allowing vibrational spectroscopic detection in capillary liquid chromatography in addition to standard UV detection. Using a flow-through microdispenser, robust and stable deposition of picoliter-sized droplets on a CaF₂ plate window was achieved. The CaF₂ window was placed on a thermostated sample holder (80 °C) mounted on a computerized x, y stage for achieving fast solvent evaporation and enabling recording of the chromatogram as a trace of deposited material. The dried residues that were formed had diameters of a few tens of micrometers and were analysed by mid-IR and Raman micro-spectroscopy. Conditions were optimized for high sensitivity of measurement and maintaining chromatographic resolution during the deposition step. Due to the destruction-free character of Raman and FTIR spectroscopy, these techniques could be applied sequentially to interrogate the same deposits. To test the usefulness of the methodology for environmental analysis, the determination and unambiguous identification of chlorinated pesticides (chlortoluron, diuron, atrazine, and terbuthylazine) in river water was used as an example, obtaining limits of identification of 2 ng analyte on-column and precision of approximately 10% RSD. The application of the developed method to spiked real river samples demonstrated the identification power of the proposed method as, in addition to the four previously studied pesticides, two additional pesticides (simazine and isoproturon) could also be detected and identified.

Keywords: HPLC; IR spectroscopy; Raman spectroscopy; Pesticides

GC-MS determination of polycyclic aromatic hydrocarbons evolved from pyrolysis of biomass by Daniele Fabbri; Alessio Adamiano; Cristian Torri (pp. 309-317).

A method for the determination of polycyclic aromatic hydrocarbons (PAHs) in liquid pyrolysate of biomass (bio-oil) was developed with attention to greenness along with accuracy. Bio-oil obtained from preparative pyrolysis at 500 °C of poplar wood as representative biomass matrix was dissolved into acetonitrile (ACN). An aliquot of the ACN solution (0.1 mg bio-oil) was added with water (20% v/v) and spiked with perdeuterated standards, then PAHs were extracted with n-hexane and separated from phenolic interferents by silica gel solid-phase extraction (SPE). All 16 priority PAHs were detected at concentrations between 7.7 µg g⁻¹ (naphthalene) and 0.1 µg g⁻¹ (benz[a]anthracene) with RSD in the 6–23% range. Recovery of perdeuterated acenaphthene, phenanthrene and chrysene was 84, 93 and 90%, respectively. Results obtained from the analysis of bio-oil were used to evaluate the performance of analytical pyrolysis conducted with a heated platinum filament in off-line configuration. Two sampling procedures were compared: (1) sorption onto silica gel followed by elution with n-hexane (Py-SPE), (2) dynamic solid-phase micro-extraction followed by fibre cleanup with aqueous ammonia (Py-SPME). Emission levels of priority PAHs could be determined by Py-SPE with RSD in the 13–45% range, while Py-SPME was unsatisfactory for quantitation. Emission levels determined by Py-SPE fell in the 6.4–0.1 µg g⁻¹ range slightly higher than those calculated from bio-oil analysis. Both Py methods were adequate for screening purposes to assess the effect of catalysts on PAH formation. In particular, they agreed to show that the content of PAHs expected in bio-oil increased dramatically when pyrolysis was conducted over HZSM-5 zeolite. Figure PAHs in the pyrolysate of poplar wood: novel procedures of bio-oil analysis and analytical pyrolysis of biomass

Keywords: Biomass; Fuel; GC-MS; Polycyclic aromatic compounds; Pyrolysis

Multimethod analysis of Iranian Ilkhanate ceramics from the Takht-e Soleyman palace by Laura Osete-Cortina; María Teresa Doménech-Carbó; Antonio Doménech; Dolores Julia Yusá-Marco; Hossein Ahmadi (pp. 319-329).

The present work describes an analytical study performed on several pieces of Iranian Ilkhanate glazed ceramics from the Takht-e Soleyman palace (Iran, thirteenth century). Several advanced instrumental techniques, including pyrolysis–gas chromatography–mass spectrometry, Fourier transform IR spectroscopy, light microscopy, X-ray diffraction, scanning electron microscopy–X-ray microanalysis and voltammetry of microparticles, were used. The results obtained led to identification of the chemical and mineralogical composition of the pastes and glazes and the colouring agents. Corrosion processes associated with the extreme burial conditions in which the pieces remained for centuries were characterized in some areas of the glazes. A drying oil was identified as the main component of the organic material that was used as the adhesive for the decorative gold sheets applied on the glazes. This finding is in good agreement with traditional recipes. Interestingly, this drying oil exhibits an unusual composition as the gold sheet preserved it from external ageing agents (light, atmosphere, etc.). Figure Tiles with cobalt blue glaze from the indoor decoration of the Takht-e Soleyman Palace (13th-15th centuries, Iran). a: 20986-8, b: 20986-10 and c:21300a

Keywords: Ilkhanate ceramics; Pyrolysis–gas chromatography–mass spectrometry; Scanning electron microscopy–energy-dispersive X-ray microanalysis; Voltammetry of microparticles; Fourier transform IR spectroscopy; X-ray diffraction

Screen-printed sensor for batch and flow injection potentiometric chromium(VI) monitoring by Raúl A. Sánchez-Moreno; M. Jesús Gismera; M. Teresa Sevilla; Jesús R. Procopio (pp. 331-338).

A disposable screen-printed electrode was designed and evaluated for direct detection of chromium(VI) in batch and flow analysis. The carbon screen-printed electrode was modified with a graphite–epoxy composite. The optimal graphite–epoxy matrix contains 37.5% graphite powder, 12.5% diphenylcarbohydrazide, a selective compound for chromium(VI), and 50% epoxy resin. The principal analytical parameters of the potentiometric response in batch and flow analysis were optimized and calculated. The screen-printed sensor exhibits a response time of 20 ± 1 s. In flow analysis, the analytical frequency of sampling is 70 injections per hour using 0.1 M NaNO₃ solution at pH 3 as the carrier, a flow rate of 2.5 mL·min⁻¹, and an injection sample volume of 0.50 mL. The sensor shows potentiometric responses that are very selective for chromium(VI) ions and optimal detection limits in both static mode (2.1 × 10⁻⁷ M) and online analysis (9.4 × 10⁻⁷ M). The disposable potentiometric sensor was employed to determine toxicity levels of chromium(VI) in mineral, tap, and river waters by flow-injection potentiometry and batch potentiometry. Chromium(VI) determination was also carried out with successful results in leachates from municipal solid waste landfills. Figure Schematic diagram of the flow system and potentiometric response peaks to chromium (VI) of the screen-printed sensor

Keywords: Chromium(VI); Screen-printed electrode; Graphite–epoxy composite; Diphenylcarbohydrazide; Flow-injection potentiometry; Potentiometry

Investigation of selective molecular interactions using two-dimensional Fourier transform IR spectroscopy by Xueyong Liu; Tao Zhou; Xiaochuan Wang; Junhua Zhang (pp. 339-343).

A novel method of studying molecular interactions is introduced. It is a method based on the framework of a two-dimensional (2D) infrared (IR) correlation spectroscopy technique with a new data pretreatment strategy. In this method, an additional external perturbation stimulates the system to cause some selective changes in the state, order, and surroundings of system constituents. The overall response of the stimulated system to the applied external perturbation leads to distinctive changes in the measured spectrum, and a series of perturbation-induced dynamic spectra are collected in a systematic manner. Such a set of dynamic spectra are then transformed into a set of 2D correlation spectra by cross-correlation analysis. Temperature was chosen as an external perturbation, and the molecular interaction between 4-aminopyridine (Apy) and methacrylic acid (MAA) was investigated by 2D IR correlation spectroscopy. Synchronous cross peaks exist between the stretching vibration of the C–O group of MAA at 1,298 and 1,202 cm⁻¹ and the C=N group of Apy at 1,531 cm⁻¹, and between the carbonyl group of MAA at 1,705 cm⁻¹ and the amino group of Apy at 3,382 and 3,212 cm⁻¹. The synchronous cross peaks are from orientation of MAA and Apy vibrations generated at the same time; the synchronization of microstructure movements in the molecules indicates that there exists strong interactions between MAA and Apy. According to 2D correlation rules, static electricity and hydrogen-bonding interactions exist between Apy and MAA. Such results were further verified by ¹H-NMR spectroscopy. The successful application demonstrates that 2D IR correlation spectroscopy may be a convenient and effective method in the study of molecular interactions. Figure Synchronous 2D IR correlation spectra of MAA-Apy in 1600–1150 cm⁻¹ region.

Keywords: Two-dimensional correlation spectroscopy; Molecular interaction; 4-Aminopyridine; Methacrylic acid

Characterisation of steroids in wooden crates of veal calves by accelerated solvent extraction (ASE®) and ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry (U-HPLC-QqQ-MS-MS) by K. Verheyden; H. Noppe; J. Vanden Bussche; K. Wille; K. Bekaert; L. De Boever; J. Van Acker; C. R. Janssen; H. F. De Brabander; L. Vanhaecke (pp. 345-355).

Illegal steroid administration to enhance growth performance in veal calves has long been, and still is, a serious issue facing regulatory agencies. Over the last years, stating undisputable markers of illegal treatment has become complex because of the endogenous origin of several anabolic steroids. Knowledge on the origin of an analyte is therefore of paramount importance. The present study shows the presence of steroid analytes in wooden crates used for housing veal calves. For this purpose, an analytical procedure using accelerated solvent extraction (ASE®), solid-phase extraction (SPE) and ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry (U-HPLC-MS-MS) is developed for the characterisation of androstadienedione (ADD), boldenone (bBol), androstenedione (AED), β-testosterone (bT), α-testosterone (aT), progesterone (P) and 17α-hydroxy-progesterone (OH-P) in wood samples. In samples of wooden crates used for housing veal calves, ADD, AED, aT and P could be identified. Using the standard addition approach concentrations of these analytes were determined ranging from 20 ± 4 ppb to 32 ± 4 ppb for ADD, from 19 ± 5 ppb to 44 ± 17 ppb for AED, from 11 ± 6 ppb to 30 ± 2 ppb for aT and from 14 ± 1 ppb to 42 ± 27 ppb for P, depending on the sample type. As exposure of veal calves to steroid hormones in their housing facilities might complicate decision-making on illegal hormone administration, inequitable slaughter of animals remains possible. Therefore, complete prohibition of wooden calf accommodation should be considered.

Keywords: Pressurised liquid extraction; Solid-phase extraction (SPE); Liquid chromatography; Mass spectrometry; Steroid analytes; Wood

Identification of additives in poly(vinylacetate) artist’s paints using PY-GC-MS by Miguel F. Silva; Maria Teresa Doménech-Carbó; Laura Fuster-López; Marion F. Mecklenburg; Susana Martin-Rey (pp. 357-367).

Commercial poly(vinyl acetate) (PVAc) paint formulations for artists include a number of compounds in addition to the PVAc polymer and pigments to improve the physical and chemical properties of the resulting product. Among the most common additives are surfactants, coalescing agents, defoamers, freeze–thaw agents and thickeners. These products significantly influence the behaviour of the dried film. Nevertheless, they are usually difficult to detect with conventional analytical methods given their low concentration. In order to identify these additives, present in the dried film as minor components, an analytical method based on in situ thermally assisted pyrolysis–silylation gas chromatography–mass spectrometry (GC-MS) using hexamethyldisilazane as a derivatisation reagent is proposed. This method improves the conventional GC-MS analysis performed by direct pyrolysis and enables the simultaneous identification of the PVAc binding medium and the additives included by the manufacturer in the commercial paint. Five different commercial PVAc paints have been analysed, namely, armour green, burnt umber, oriental red, raw umber and white from Flashe®. Internal plasticiser VeoVa consisting of C₁₀ fatty acids with highly branched chains has been recognised from the MS spectra. On the other hand, the differences found in the additive content of the studied paints, in particular the poly(ethylene glycol)-type surfactant, are in good agreement with their mechanical properties. Figure Picture of armour green Flashe® paint sample breaking in the mechanical tester’s gauge. The photo evidences the type of break these samples experience. Rather than a clean break, the sample experiences several simultaneous fractures with a saw-tooth-like pattern

Keywords: Paints; PVAc; Additives; PEG; Py-GC-MS; HMDS

Volatile organic compounds in paper—an approach for identification of markers in aged books by Elvira M. Gaspar; José C. Santana; João F. Lopes; Marcos B. Diniz (pp. 369-380).

Volatile organic compounds emitted from historical books made from cotton/linen rag and wood pulp paper have been studied. Different profiles were obtained using different solid-phase microextraction (SPME) fibres to access the compounds involved in the decomposition reactions occurring in cotton/linen rag and wood pulp paper upon natural ageing and precocious/accelerated degradation. Contact headspace solid-phase extraction coupled with gas chromatography/time-of-flight mass spectrometry (GC-TOF-MS) was improved as a non-destructive methodology for the analysis of historical books. Potential markers of cellulose degradation—linear hydrocarbons, linear aldehydes, and 2-furfural—together with potential markers of cotton/linen rag paper (isopropylic esters) were identified. Chiral analysis (SPME-c-GC-TOF-MS) showed that only the enantiomer (S)-2-ethyl-1-hexanol is present as an emanation compound in both types of paper. Validation studies for a larger number of books are being done. Figures 1–3 Portuguese old books made from cotton/linen rag paper.

Keywords: Paper; Wood pulp paper; Cotton/linen rag; Cellulose; Wood pulp; VOC; Paper ageing

CMOS arrays as chemiluminescence detectors on microfluidic devices by Eunice R. G. O. Rodrigues; Rui A. S. Lapa (pp. 381-388).

A simple, low-cost process to integrate complementary metal oxide semiconductor array detectors (CMOSAD) for chemiluminescence is presented, evaluated, and applied to the determination of nitrite in ground water samples. CMOS arrays of different brands (obtained from commercial image sensors) were adapted as chemiluminescence detectors on microfluidic devices. The performance of the CMOSADs was evaluated in the visible zone of the spectrum using a tungsten halogen lamp as light source. Intrinsic parameters assessed included signal stability, spectral response, dark current, and signal-to-noise ratio. Thereafter, the CMOSADs were integrated on microfluidic devices and their performances in quantitative analysis were assessed with the chemiluminometric reaction of hydrogen peroxide with luminol, catalyzed with hexacyanoferrate (III). The parameters assessed were sensitivity, linear range, detection limit, reproducibility, correlation coefficient of the calibration curves, and baseline drift during measurements. The CMOSAD with the best performance was selected to assess the applicability of the developed microfluidic devices with the integrated detector. The microfluidic system permitted the determination of nitrite with both good precision and good recovery values in the analysis of ground water samples. Integration was easily achieved and enabled the development of a simple, low-cost, and feasible alternative to conventional detectors.

Keywords: Microfluidic device; CMOS array; Chemiluminescence detector; PMMA; Nitrite determination; Multi-pumping

Application of the new electroanalytical technique AGNES for the determination of free Zn concentration in river water by Francesca Zavarise; Encarnació Companys; Josep Galceran; Giancarla Alberti; Antonella Profumo (pp. 389-394).

Absence of gradients and Nernstian equilibrium stripping (AGNES) is a recently developed electroanalytical technique specifically designed for the direct determination of free concentrations of metal ions. AGNES is applied here to the determination of free Zn concentration in a river water sample. The method has been validated with synthetic solutions of low ionic strengths containing Zn and 2,6-pyridinedicarboxylic acid and then applied to synthetic river waters and to a natural sample collected from Besòs River in Montcada i Reixac (Catalonia, North-Eastern Spain). In the river sample, an average free Zn concentration of 12.8(4) nM was obtained, while the total dissolved Zn concentration was 0.51(8) μM. To control and maintain pH and pCO₂ constant during AGNES measurements, a novel device for N₂/CO₂ mixed purging has been developed.

Keywords: Speciation; AGNES; River water; Synthetic water; Zn; Purging system

Determination of vanadium(V) in the particulate matter of emissions and working areas by sequential dissolution and solid-phase extraction by M. Sturini; F. Maraschi; L. Cucca; G. Spini; G. Talamini; A. Profumo (pp. 395-399).

A method based on selective sequential dissolutions is proposed to determine total vanadium(V) in particulate matter of emissions and working areas at concentrations 1,000 times lower than the threshold limit of 0.05 mg m⁻³. Separation and preconcentration of vanadium(V) has been achieved by solid-phase extraction on Chelex 100 resin. Possible influence of the matrix has been investigated for two standard reference materials (SRMs), NIST SRM 1648 and BCR-038, before and after spiking, with vanadium(V) recovery in the range 97–103%.

Keywords: Vanadium(V); Emissions; Sequential dissolution; Solid-phase extraction

Ultra-fast HPLC-ICP-MS analysis of oxaliplatin in patient urine by Gunda Koellensperger; Stephan Hann (pp. 401-406).

A novel method for rapid HPLC-ICP-MS analysis of oxaliplatin in human urine was developed implementing a stationary HPLC phase with a particle size of 1.8 µm. The method allowed a cycle time of <1 min at a HPLC flow rate of 0.9 mL min⁻¹. Procedural limits of detection of 0.05 µg L⁻¹ oxaliplatin (150 fg on column) were obtained. Analysis of oxaliplatin in patient urine showed that accurate quantification of the intact drug demanded for storage at −80 °C and rapid measurement after thawing.

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Analytical and Bioanalytical Chemistry (v.397, #1)

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Analytical and Bioanalytical Chemistry (v.397, #1)