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Analytical and Bioanalytical Chemistry (v.379, #1)

Spectroscopy challenge 6 by Silvia Paasch; Reiner Salzer (pp. 1-2).
Solution to microfabrication challenge by Marc J. Madou (pp. 3-3).

Radiofrequency glow-discharge devices for direct solid analysis by Jorge Pisonero; José M. Costa; Rosario Pereiro; Nerea Bordel; Alfredo Sanz-Medel (pp. 17-29).
The enormous potential of radiofrequency glow discharges (rf-GD) as photon, atom, or ion sources, coupled to spectrometric techniques, for rapid direct analysis of almost any conductor, semiconductor, or insulating material with good in-depth resolution has been demonstrated world-wide. This outstanding performance has prompted a great effort to develop and characterise rf-GD for direct materials analysis in recent years. The state of the art of rf-GD coupled to atomic absorption spectrometry, optical emission spectrometry, and mass spectrometry for direct solid analysis is reviewed here. A description of the principles of operation of the rf-GD and attempts to model these discharges are also given. Rf-GD instrumentation, both developed at research laboratories and commercially available, is described. Several practical examples are given demonstrating the capabilities of these techniques for bulk and depth-profile analysis. Finally, the research gaps to be filled for full implementation of rf-GD spectrometric techniques in industry and research centres alike for materials science studies and technical development are discussed.

Keywords: Radiofrequency glow-discharge device; Direct solid analysis; Atomic absorption spectrometry; Optical emission spectrometry; Mass spectrometry


Comparison of three different phosphorescent methodologies in solution for the analysis of naphazoline in pharmaceutical preparations by Beatriz Cañabate Díaz; Silvia Casado Terrones; Antonio Segura Carretero; José Manuel Costa Fernández; Alberto Fernández Gutiérrez (pp. 30-34).
We present results from a comparative study of three proposed phosphorimetric methods for determination of naphazoline (NPZ) in solution. The first method is based on use of micelles to stabilize phosphorescence signals in solutions at room temperature (MS-RTP). The second is based on the use of a heavy atom salt and sodium sulfite as an oxygen scavenger to obtain room-temperature phosphorescence (HAI-RTP) in solution. The last method employs an optical sensor for NPZ based on the phosphorescent properties of the analyte on a solid sensor phase. The aim of this work was to compare time consumption, simplicity, sensitivity, selectivity, detection, and quantification limits for use of these three phosphorimetric methods to determine naphazoline in pharmaceutical preparations. The most simple, sensitive, and reproducible of the three methods for naphazoline analysis is the HAI-RTP method. Detection limits are 4.9, 1.7, and 9.4 ng mL−1, respectively, for the MS-RTP, HAI-RTP, and optosensor methods.

Keywords: Phosphorimetry; Pharmaceutical analysis; Naphazoline


Determination of oil and water content in olive pomace using near infrared and Raman spectrometry. A comparative study by Barbara Muik; Bernhard Lendl; Antonio Molina-Díaz; Luis Pérez-Villarejo; María José Ayora-Cañada (pp. 35-41).
Near infrared (NIR) reflectance and Raman spectrometry were compared for determination of the oil and water content of olive pomace, a by-product in olive oil production. To enable comparison of the spectral techniques the same sample sets were used for calibration (1.74–3.93% oil, 48.3–67.0% water) and for validation (1.77–3.74% oil, 50.0–64.5% water). Several partial least squares (PLS) regression models were optimized by cross-validation with cancellation groups, including different spectral pretreatments for each technique. Best models were achieved with first-derivative spectra for both oil and water content. Prediction results for an independent validation set were similar for both techniques. The values of root mean square error of prediction (RMSEP) were 0.19 and 0.20–0.21 for oil content and 2.0 and 1.8 for water content, using Raman and NIR, respectively. The possibility of improving these results by combining the information of both techniques was also tested. The best models constructed using the appended spectra resulted in slightly better performance for oil content (RMSEP 0.17) but no improvement for water content.

Keywords: Raman; Near Infrared; Oil content; Water content; Olive pomace; Partial least squares (PLS) regression


Analysis of bulk and inorganic degradation products of stones, mortars and wall paintings by portable Raman microprobe spectroscopy by M. Pérez-Alonso; K. Castro; I. Martinez-Arkarazo; M. Angulo; M. A. Olazabal; J. M. Madariaga (pp. 42-50).
This work reports the use of a portable Raman microprobe spectrometer for the analysis of bulk and decaying compounds in carbonaceous materials such as stones, mortars and wall paintings. The analysed stones include limestone, dolomite and carbonaceous sandstone, gypsum and calcium oxalate, both mono- and dihydrated, being the main inorganic degradation products detected. Mortars include bulk phases with pure gypsum, calcite and mixtures of both or with sand, soluble salts being the most important degradation products. The pigments detected in several wall paintings include Prussian blue, iron oxide red, iron oxide yellow, vermilion, carbon black and lead white. Three different decaying processes have been characterised in the mortars of the wall paintings: (a) a massive absorption of nitrates that reacted with calcium carbonate and promoted the unbinding of pigment grains, (b) the formation of black crusts in the vault of the presbytery and (c) the thermodecomposition of pigments due to a fire.

Keywords: Portable Raman spectroscopy; Bulk and degradation analysis; Stone; Mortars; Wall paintings


Urban ozone measurements using differential optical absorption spectroscopy by J. A. Morales; J. Treacy; S. Coffey (pp. 51-55).
In order to improve the air quality in Europe the European Commission has issued a number of directives with regard to acceptable levels of a range of gaseous pollutants, which includes ozone. Therefore, monitoring of this compound is necessary to comply with EU legislation, to provide improved pollution warnings for those who are sensitive to air pollutants as well as providing valuable data for environmental planning. Open-path spectroscopic techniques, such as differential optical absorption spectroscopy (DOAS), are ideal for monitoring pollutants because of the advantages they offer over classical methods and point-source analysers. A DOAS system has been installed in Dublin city centre to monitor a range of criteria pollutants including ozone. Observations of urban background ozone concentrations are presented. The measurements are compared with those obtained using a UV point-source analyser and are presented in the context of the current EU directive. The influence of trans-boundary pollution from mainland Europe leading to ozone episodes is also discussed. Observations of high ozone during this measurement campaign coincided with the influx of photochemically polluted air masses which originated over continental Europe. For the analysed time interval, the data suggest that the ground ozone level in Dublin might be significantly influenced by long-range transport from the United Kingdom and continental Europe.

Keywords: Differential optical absorption spectroscopy (DOAS); Open-path spectroscopy; Ozone; Pollution; Trans-boundary pollution


NMR study of some diastereomeric nucleoside-3′-thiophosphate derivatives in solution by Eszter Gács-Baitz; Mária Kajtár-Peredy; Gyula Sági (pp. 56-59).
The conformational properties of diastereomeric P-modified nucleotides are reported as reflected by different NMR parameters. Some conformational trends can be rationalized by consideration of the 3 J(C4′,P) and 3 J(C2′,P) coupling values of the isomers and the nature of the substituent on the phosphorus. Configurational assessment of the phosphorus is inferred from NOE experiments. The effects of temperature, solvent and size of substituents are presented.

Keywords: Modified nucleotides; 13C-31P coupling constants; Conformational properties


Determination of trace amounts of gold in acid-attacked environmental samples by atomic absorption spectrometry with electrothermal atomization after preconcentration by Ján Medveď; Marek Bujdoš; Peter Matúš; Jana Kubová (pp. 60-65).
A method for determination of trace amounts of gold in environmental samples (rocks, soils, sediments, and waters) by atomic absorption spectrometry with electrothermal atomization (ETAAS) after preconcentration using a chelating sorbent Spheron Thiol 1000 is described. The method accurately determines gold between 0.001 and several tens of grams per ton in samples having complex variations in mineralogy. Pulverized samples are roasted at 650°C to oxidize any sulfide and/or carbonaceous material. Samples are then subjected to a series of acid treatments to eliminate any silica matrix and to dissolve the sample. The Spheron Thiol 1000 is added to the sample solution, and then with sorbed gold is filtered out, washed, and ignited at 550°C. The residue is dissolved in aqua regia, evaporated, dissolved in distilled water, transferred to a volumetric flask, and analyzed by ETAAS.The limits of detection of gold, based on the 3σ definition, were 0.5 ng g−1 for 10-g samples (rocks, sediments, soils) and 0.05 ng mL−1 for 1-L water samples. Precision of determination expressed by the relative standard deviation varied from 2.9% to 16.4%. The accuracy of the method is verified by analysis of certified reference materials. The obtained analytical results are in good agreement with attested values. The developed method was applied for gold determination in environmental samples affected by the acidification (acid mine drainage which is mainly a product of pyrite oxidation) from an open quartzite mine in the Šobov region situated NE of the city of Banská Štiavnica (Slovakia).

Keywords: ETAAS; Gold determination; Preconcentration; Spheron Thiol 1000; Environmental samples


Direct determination of arsenic and antimony in naphtha by electrothermal atomic absorption spectrometry with microemulsion sample introduction and iridium permanent modifier by Ricardo J. Cassella; Bruno Alberto R. S. Barbosa; Ricardo E. Santelli; Alessandra T. Rangel (pp. 66-71).
This paper reports the determination of arsenic and antimony in naphtha by employing electrothermal atomic absorption spectrometry (ETAAS) as the analytical technique. In order to promote the direct determination of the analytes in the very volatile naphtha, the formation of a microemulsion with different surfactants (Triton X-100 and Brij-35) and different chemical modification strategies were tested. The results indicated that Triton X-100 is the best emulsification agent for naphtha in both As and Sb determination when it is employed at a concentration of 1% w/v in the microemulsion. Under these conditions, the microemulsion was stabile for at least 2 h. By using Brij-35 it was possible to achieve good stability only in the first 15 min. Among all chemical modification approaches investigated (Ir permanent modifier, W-Ir permanent modifier, and Pd modifier), the Ir permanent modifier provided better sensitivity for both analytes and allowed a higher pyrolysis temperature, which decreased the background signals at lower levels. Under the best conditions established in this work, an RSD of 4.6% (20 μg L−1) and a detection limit of 2.7 μg L−1 were observed for arsenic. For antimony, an RSD of 4.0% (20 μg L−1) and a detection limit of 2.5 μg L−1 were obtained. The accuracy of the procedure was assessed by analyzing spiked samples of naphtha from different origins.

Keywords: Electrothermal atomic absorption spectrometry; Naphtha; Arsenic; Antimony; Microemulsion


Determination of vanadium in mussels by electrothermal atomic absorption spectrometry without chemical modifiers by Y. Saavedra; P. Fernández; A. González (pp. 72-76).
A method was developed for the quantitative determination of total vanadium concentration in mussels via electrothermal atomic absorption spectrometry (ETAAS). After the microwave digestion of the samples, a program using temperatures of 1600 °C and 2600 °C for ashing and atomization respectively, without any matrix modifiers, allowed us to obtain results that were satisfactory since they agreed closely with certified reference material values. The detection limit was 0.03 mg kg−1 (dry weight), indicating that the method is suitable for the analysis of mussel samples. This determination was compared with matrix modifiers that have been reported previously. The method was applied to various cultivated and wild mussels from the Galician coast, yielding levels below 1 mg kg−1 (wet weight).

Keywords: Vanadium; Electrothermal atomic absorption spectrometry; Chemical modifier; Wild mussel; Cultivated mussel


Continuous ultrasound-assisted extraction coupled to a flow injection-flame atomic absorption spectrometric system for calcium determination in seafood samples by A. Moreno-Cid; M. C. Yebra (pp. 77-82).
Calcium was extracted on-line from solid seafood samples by a simple and rapid continuous ultrasound-assisted extraction system. This system is connected to a flow injection manifold, which allows the on-line flame atomic absorption spectrometric determination of calcium. This method enables the analysis of solid samples avoiding time-consuming traditional sample preparation methods and their inherent errors. The on-line manifold for calcium determination is the simplest possible, because a volume of 250 μL of acid extract is injected into an ultrapure water carrier stream. The acid extract was diluted on-line with lanthanum, which also acts as masking agent in order to avoid chemical interferences. The continuous monitoring of the calcium signal was accomplished by flame atomic absorption spectrometry. A Plackett-Burman experimental design was used for the optimisation of the continuous leaching procedure. The method allowed a total sampling frequency of 40 samples per hour, with a relative standard deviation for the complete procedure of 0.9% (for a sample containing 3414.35 mg/kg calcium (dry mass)). The limit of detection was found to be 44.4 mg/kg (dry mass) for 5 mg of sample. The analytical procedure was applied to real seafood samples.

Keywords: Continuous ultrasound-assisted extraction system; Flame atomic absorption spectrometry; Calcium determination; Seafood


Multicommutation as an environmentally friendly analytical tool in the hydride generation atomic fluorescence determination of tellurium in milk by Eva Ródenas-Torralba; Patricia Cava-Montesinos; Ángel Morales-Rubio; M. Luisa Cervera; Miguel de la Guardia (pp. 83-89).
The aim of this study is to show the advantages of the emerging multicommutation methodology based on the use of solenoid valves for Te determination in milk by hydride generation atomic fluorescence spectrometry (HG-AFS). The delivery of a series of alternating sequential insertions of small volumes of samples and reagents gives rise to new hydrodynamic processes and exciting analytical potentials by controlling the time of flow through the on/off-switched solenoid valves. This drastically reduces the reagent consumption by a factor of 4 and the generation of effluents (590 mL h−1 instead of 750 mL h−1 generated by the continuous-mode measurement) and also provides an improvement in the laboratory productivity by an increase of the sample throughput (85 h−1 compared to 20 h−1 found in the continuous mode). So, multicommutation is an environmentally and economically sustainable alternative to the methodology based on continuous measurements. The multicommutation-based method developed was applied to tellurium determination in commercially available milk samples; a calibration range of 0.0–0.5 ng mL−1 and a detection limit of 0.20 ng L−1 with average relative standard deviation of 2.1% were found. Comparable results were obtained for a series of samples using both continuous and multicommutation HG-AFS modes.

Keywords: Multicommutation; Tellurium determination; Atomic fluorescence spectrometry; Hydride generation; Milk analysis


Simultaneous determination of bismuth and tellurium in steels by high power nitrogen microwave induced plasma atomic emission spectrometry coupled with the hydride generation technique by Akihiro Matsumoto; Tadashi Shiozaki; Taketoshi Nakahara (pp. 90-95).
An annular-shaped, high power nitrogen microwave induced plasma (N2-MIP) produced at atmospheric pressure by an Okamoto cavity, as a new excitation source for atomic emission spectrometry (AES), has been used for the simultaneous determination of bismuth and tellurium in steels with the hydride generation method. Under the optimized experimental conditions, the best attainable detection limits at the Bi I 195.389 nm and Te I 200.200 nm lines were 110 and 86 ng/ml for bismuth and tellurium, respectively. The linear dynamic ranges for bismuth and tellurium were 300 to 30,000 ng/ml. The presence of several diverse elements was found to cause a more or less depressing interference with the proposed technique. When bismuth and tellurium in steels were determined, a large amount of Fe(III) in the solution caused a severe depressing interference, while the presence of Fe(II) showed little or no significant interference. Of the several interference-releasing agents examined, l-ascorbic acid was found to be the most preferable to reduce Fe(III) to Fe(II) prior to hydride generation. The concentrations of bismuth and tellurium in steels were determined by the proposed technique. The results obtained by this method were in good agreement with their certified values.

Keywords: High power nitrogen microwave induced plasma; Atomic emission spectrometry; Hydride generation technique; Bismuth; Tellurium; l-ascorbic acid; Steels


Chemical partitioning of aluminium in rocks, soils, and sediments acidified by mining activity by Peter Matúš; Jana Kubová; Marek Bujdoš; Vladimír Streško; Ján Medveď (pp. 96-103).
The work presented describes the application of different analytical approaches for study of aluminium mobility in rock, soil, and sediment samples affected by mining activity (secondary quartzites with sulfidic deposits). For this purpose we used a combination of the single extractions, the optimized BCR three-step sequential extraction procedure (SEP), and reactive aluminium determination after chelating ion-exchange on Ostsorb (Iontosorb) Salicyl by a batch technique with flame atomic absorption spectrometry quantification. The single extraction agents H2O, KCl, NH4Cl, and BaCl2 were found to be the best for the quantitative estimation of the aluminium mobility in rocks, soils, and sediments caused by acidification of the environment. This fact was confirmed by reactive aluminium determination in the same samples. The vast majority of the aluminium content of samples after application of the optimized BCR three-step SEP is in the residues. The available fraction of aluminium extracted by dilute CH3COOH in the first step of this procedure correlates with the reactive aluminium content. The amounts of aluminium released in the second and the third steps and the sums from steps 1–3 of this procedure are closely associated with the aluminium content values obtained by the single dilute HCl leach. The accuracy of results obtained was verified with only informative values for individual fractions of the BCR three-step SEP because of the absence of suitable certified or standard reference materials. The amounts of the reactive aluminium determined in samples was in the range 12–82% of total soluble Al in the filtered H2O extracts. It was confirmed that the acidified polluted samples contain the most of reactive Al content, which is responsible for its toxicity.

Keywords: Aluminium partitioning; Fractionation; Speciation; Extraction; Ion-exchange; Ostsorb (Iontosorb) Salicyl


Use of a simplified generalized standard additions method for the analysis of cement, gypsum and basic slag by slurry nebulization ICP-OES by Ljiljana Marjanovic; Robert I. McCrindle; Barend M. Botha; Herman J. Potgieter (pp. 104-107).
The simplified generalized standard additions method (GSAM) was investigated as an alternative method for the ICP-OES analysis of solid materials, introduced into the plasma in the form of slurries. The method is an expansion of the conventional standard additions method. It is based on the principle of varying both the sample mass and the amount of standard solution added. The relationship between the sample mass, standard solution added and signal intensity is assumed to be linear. Concentration of the analyte can be found either geometrically from the slope of the two-dimensional response plane in a three-dimensional space or mathematically from the ratio of the parameters estimated by multiple linear regression. The analysis of a series of certified reference materials (CRMs) (cement CRM-BCS No 353, gypsum CRM-Gyp A and basic slag CRM No 382/I) introduced into the plasma in the form of slurry is described. The slurries contained glycerol and hydrochloric acid and were placed in an ultrasonic bath to ensure good dispersion. “Table curve 3D” software was used to fit the data. Results obtained showed that the method could be successfully applied to the analysis of cement, gypsum and slag samples, without the need to dissolve them. In this way, we could avoid the use of hazardous chemicals (concentrated acids), incomplete dissolution and loss of some volatiles. The application of the simplified GSAM for the analysis did not require a CRM with similar chemical and mineralogical properties for the calibration of the instrument.

Keywords: Slurry nebulization; Cement; Gypsum; Slag; ICP-OES


Fractionation of various elements in CRMs and in polluted soils by J. Kubová; V. Streško; M. Bujdoš; P. Matúš; J. Medved’ (pp. 108-114).
An optimised BCR three steps sequential extraction procedure (BCR SEP) and several single extractions with KCl, NH4Cl, Na4P2O7 and 0.5 mol L−1 HCl were used for the fractionation of Al, Cu, Fe, Mn, Pb and Zn in CRMs and in samples from a mining area with sulphidic deposits. A good interlaboratory comparability was obtained for Cu, Pb and Zn in CRM 483, CRM 701, SRM 2710 and SRM 2711 by BCR SEP. The reliability of the results obtained is also very satisfactory. Some differences were found between our results and the indicative data for Al and Fe fractionation. However, serious discrepancies were found for Mn, not only for individual steps of the fractionation, but for the data obtained overall (sum of 1–3 steps), and for the total concentration as well. Our results could be utilized as a contribution to the existing indicative values for CRM 483, SRM 2710 and SRM 2711 for interlaboratory study. Moreover, data for the fractionation of elements mentioned above for CRM 701 are first presented here.A high correlation between 0.5 mol L−1 of HCl-extractable amounts of the elements studied, and the sum of the three steps of BCR SEP in acid sulphatic weathering products and naturally acidified soils was established, which allows us to suggest this rapid and cost-effective single extraction procedure as a valuable tool in contamination assessment.

Keywords: Optimised BCR sequential extraction; Single extraction; CRMs; Acid soils; Reliability of procedures


Sampling modulation technique in radio-frequency helium glow discharge emission source by use of pulsed laser ablation by Tariq Mahmood Naeem; Hideyuki Matsuta; Kazuaki Wagatsuma (pp. 115-119).
An emission excitation source comprising a high-frequency diode-pumped Q-switched Nd:YAG laser and a radio-frequency powered glow discharge lamp is proposed. In this system sample atoms ablated by the laser irradiation are introduced into the lamp chamber and subsequently excited by the helium glow discharge plasma. The pulsed operation of the laser can produce a cyclic variation in the emission intensities of the sample atoms whereas the plasma gas species emit the radiation continuously. The salient feature of the proposed technique is the selective detection of the laser modulation signal from the rest of the continuous background emissions, which can be achieved with the phase sensitive detection of the lock-in amplifier. The arrangement may be used to estimate the emission intensity of the laser ablated atom, free from the interference of other species present in the plasma. The experiments were conducted with a 13.56 MHz radio-frequency (rf) generator operated at 80 W power to produce plasma and the laser at a wavelength of 1064 nm (pulse duration:34 ns, repetition rate:7 kHz and average pulse energy of about 0.36 mJ) was employed for sample ablation. The measurements resulted in almost complete removal of nitrogen molecular bands (N2 + 391.44 nm). Considerable reduction (about 75%) in the emission intensity of a carbon atomic line (C I 193.03 nm) was also observed.

Keywords: Radio-frequency glow discharge; Laser ablation; Copper; Carbon; Nitrogen


Application of a simple and sensitive GC–MS method for determination of morphine in the hair of opium abusers by O. Sabzevari; Kh. Abdi; M. Amini; A. Shafiee (pp. 120-124).
Thirty hair samples were collected from male opioid abusers for whom the presence of morphine in their urine samples was confirmed by thin layer chromatography (TLC). The hair samples were decontaminated by washing with isopropanol, deionized water, and isopropanol, dried at room temperature, and cut into small pieces. Samples of the latter (30 mg ) were digested by incubation in a mixture of methanol–trifluoroacetic acid (9:1) for 18 h at 45 °C and sonicated to improve the extraction process. The methanolic phase was evaporated to dryness under a stream of nitrogen at 50 °C. The sample was derivatized by addition of N-methyl-N-trimethylsilyltrifluoroacetamide (MSTFA) and 1% trimethyliodosilane (TMIS) at 70 °C for 20 min, with sonication. Derivatized samples (1 μL) were injected into a gas chromatograph–mass spectrometer (GC–MS) system fitted with a capillary column; the Finnigan MS was operated in SIM mode. Naltrexone was used as internal standard (IS). The masses of the ions selected for morphine and naltrexone were 429 and 557, respectively. The limit of quantitation was set at 0.03 ng mg−1 hair. By using the above procedure we detected morphine in all the samples examined, in the concentration range 0.26–10.31 ng mg−1 hair.

Keywords: Detection; Determination; Hair analysis; Opium abusers; Morphine; GC–MS; SIM


Determination of fifteen priority phenolic compounds in environmental samples from Andalusia (Spain) by liquid chromatography–mass spectrometry by J. L. Martínez Vidal; A. Belmonte Vega; A. Garrido Frenich; F. J. Egea González; F. J. Arrebola Liebanas (pp. 125-130).
This work describes the optimisation of a method to determinate fifteen phenolic compounds in waters, sediments and biota (green marine algae) by liquid chromatography coupled to mass spectrometry (LC-MS) with atmospheric pressure chemical ionisation (APCI) in the negative mode. The LC separations of the studied compounds and their MS parameters were optimised in order to improve selectivity and sensitivity. Separation was carried out with a C18 column using methanol and 0.005% acid acetic as mobile phase in gradient mode. The molecular ion was selected for the quantitation in selective ion monitoring (SIM) mode. A solid-phase extraction (SPE) method was applied in order to preconcentrate the target analytes from water samples. However, extraction of the compounds from sediment and biota samples was carried out by liquid–solid extraction with methanol/water after studying the influence of other organic solvents. In addition, a clean-up step by SPE with HLB Oasis cartridges was necessary for sediments and biota. The proposed analytical methodology was validated in the target environmental matrices by the analysis of spiked blank matrix samples. Detection limits were 10–50 ng L−1 for water, 1–5 μg kg−1 for sediments and 2.5–5 μg kg−1 for biota samples. Good recoveries and precision values were obtained for all matrices. This methodology has been successfully applied to the analysis of incurred water, sediment and biota samples from Andalusia (Spain).

Keywords: Phenolic compounds; Liquid chromatography; Mass spectrometry; Environmental samples


New data on the mobility of Pt emitted from catalytic converters by Daniel Fliegel; Zsolt Berner; Detlef Eckhardt; Doris Stüben (pp. 131-136).
The mobility and speciation of Pt was investigated in dust deposited in highway tunnels and in gully sediments. For this, a sequential extraction technique was used in combination with a microwave digestion procedure, followed by detection of Pt with high resolution ICP-MS. A digestion procedure using HNO3/HCl/H2O2 was developed and its efficiency tested for environmental materials. Total Pt contents ranged from approximately 100 to 300 μg/kg. The high share of chemically mobile Pt in the tunnel dust (up to about 40%) indicates that Pt is predominantly emitted in a mobile form from the converter. The absence of a mobile fraction in the gully sediment is explained by the elution of Pt by run-off. Except for the mobile and easily mobilised fractions none of the other fractions of the sequential extraction contains Pt, neither in the dust samples nor in the gully sediment.

Keywords: Platinum; Sequential extraction; Dust deposits; Catalytic converters


A new instrument adapted to in situ Raman analysis of objects of art by P. Vandenabeele; T. L. Weis; E. R. Grant; L. J. Moens (pp. 137-142).
The analysis of precious artefacts and antiquities demands care in order to minimise the risk of accidental damage during measurement. Mobile fibre-optic-based Raman instruments offer a means to avoid destructive sampling and eliminate the need to transport artefacts for spectrochemical analysis. In this work we present a new mobile instrument developed and optimised for the in situ Raman investigation of objects of art and antiquities. The instrument is controlled by a portable computer. Selected mounts cover many types of artefacts. Newly written software routines organise spectra together with measurement parameters and facilitate calibration of the instrument. The present paper describes this new Raman instrument and discusses some challenges in the transition from a laboratory environment to in situ investigations in museums.

Keywords: Fibre optics; In situ analysis of objects of art and antiquities; Mobile Raman spectroscopy; Pigment analysis


Removal of major interference sources in aqueous near-infrared spectroscopy techniques by Da Chen; Bin Hu; Xueguang Shao; Qingde Su (pp. 143-148).
This work describes a hybrid procedure for eliminating major interference sources in aqueous near-infrared (NIR) spectra, that include aqueous influence, noise, and systemic variations irrelevant to concentration. The scheme consists of two parts: extension of wavelet prism (WPe) and orthogonal signal correction (OSC). First, WPe is employed to remove variations due to aqueous absorbance and noise; then OSC is applied to remove systemic spectral variations irrelevant to concentration. Although water possesses strong absorption bands that overshadow and overlap the absorption bands of analytes, along with noise and systematic interference, successful calibration models can be generated by employing the method proposed here. We show that the elimination of major interference sources from the aqueous NIR spectra results in a substantial improvement in the precision of prediction, and reduces the required number of PLS components in the model. In addition, the strategy proposed here can be applied to various analytical data for quantitative purposes as well.

Keywords: Extension of wavelet prism (WPe); Orthogonal signal correction (OSC); Multivariate calibration; Aqueous near-infrared spectrum


Estimation of binding constants between ristocetin and teicoplanin and peptides using on-column ligand derivatization coupled to affinity capillary electrophoresis by Maryam Azad; Abby Brown; Isba Silva; Frank A. Gomez (pp. 149-155).
This work utilizes on-column ligand synthesis and affinity capillary electrophoresis (ACE) to determine binding constants (K b) of 9-flourenylmethyloxy carbonyl (Fmoc)-amino acid derivatives to the glycopeptide antibiotics ristocetin (Rist) and teicoplanin (Teic). In this technique, two separate plugs of sample are injected on to the capillary column and electrophoresed. The initial sample plug contains a d-Ala-d-Ala terminus peptide and either one or two non-interacting standard(s). The second plug contains a Fmoc-amino acid-N-hydroxysuccinimide (NHS) ester. The electrophoresis is then carried out with an increasing concentration of Rist or Teic in the running buffer. Upon electrophoresis the initial d-Ala-d-Ala peptide reacts with the Fmoc-amino acid yielding a new Fmoc-amino acid-d-Ala-d-Ala peptide derivative. Continued electrophoresis results in the binding of Rist or Teic to the Fmoc-amino acid-d-Ala-d-Ala peptide derivatives. Analysis of the change in the relative migration time ratio (RMTR) or electrophoretic mobility (μ) of the Fmoc-amino acid-d-Ala-d-Ala peptide derivatives relative to the non-interacting standards, as a function of the concentration of Rist and Teic, yields a value for K b. These findings demonstrate the advantage of coupling on-column ligand synthesis to ACE for estimating binding parameters between antibiotics and ligands.

Keywords: Ristocetin; Teicoplanin; Affinity capillary electrophoresis; Binding constants


Modification of the Limulus amebocyte lysate assay for the analysis of glucan in indoor environments by Mark Foto; Jonathan Plett; Joanne Berghout; J. David Miller (pp. 156-162).
β-1,3-d -Glucan is a biologically active component mainly from fungi that has been shown in several studies to be related to respiratory health outcomes from damp building exposures. Here, we report the development and application of a method for the analysis of the glucan extracted in 0.5 N NaOH solution making use of an available preparation of Limulus amebocyte lysate (LAL). The method yields reproducible β-1,3-d -glucan measurements from samples of outdoor air, yeast cells, fungal spore preparations and ragweed pollen, and is more sensitive than competing measurements. The LAL-based measurement compared favourably to that based on size-exclusion chromatography using UV and refractive index detection. Growth conditions of the fungi did not materially change the concentrations of glucan in spores indicating that this is a stable property. Glucan content was proportional to spore surface area; however, some species contain higher relative spore glucan contents.

Keywords: Limulus amebocyte lysate; beta-Glucan; Fungal spores; Ragweed pollen; Baker’s yeast; Size-exclusion chromatography; Indoor air


Assessment of total effective xenoestrogen burden in adipose tissue and identification of chemicals responsible for the combined estrogenic effect by Mariana F. Fernández; Ana Rivas; Fátima Olea-Serrano; Isabel Cerrillo; José M. Molina-Molina; Patricia Araque; José L. Martínez-Vidal; Nicolas Olea (pp. 163-170).
Test systems to screen for estrogenicity and appropriate biomarkers of human exposure are required for epidemiological studies of endocrine disruption. We addressed these issues by developing and standardising a method to assess the total estrogenic xenobiotic burden in human adipose tissue. In this study, which is the continuation of a previous work, we have improved the protocol for extensive fractionation of a higher number of tissue samples in order to investigate bioaccumulated xenoestrogens that are candidates for estrogenicity and to assess their combined estrogenic effect. This was achieved by extensive HPLC separation of xenoestrogens from endogenous hormones followed by testing of individual fractions in the E-Screen test for estrogenicity. Organochlorine pesticides, PCBs and halogenated bisphenols and alkylphenols were collected in the most lipophilic fractions, followed by progestins, androgens and estradiol esters, and then by steroidal estrogens; phyto- and myco-estrogens were collected around the end of the run. These results were confirmed by exhaustive chemical analysis. In 458 human adipose tissue samples, the total effective xenoestrogen burden was positive in 75% of samples in the pooled fraction that contained organohalogenated xenoestrogens (mean 515.3 pM Eeq/g lipid; range 0–14.5 nM) and in 82% of samples in the pooled fraction where natural estrogens eluted (mean 696.6 pM Eeq/g lipid; range 0–12.9 nM). Organochlorine pesticides emerged as candidate chemicals for the estrogenicity of the first pooled fraction, because DDT and derivatives were present in 98.3% of the samples. However, no correlation was found between the concentration of any single chemical and the estrogenicity determined in the bioassay. There may be several reasons for this lack of concordance: (i) the estrogenic effects depicted in the E-Screen bioassay are a consequence of the combined effect of several organohalogens or (ii) the proliferative effect is due to other chemicals not measured. Because additive, synergistic or antagonistic mechanisms may account for the final effect observed in the pooled fractions, the approach proposed in this work is more appropriate for exposure assessment in epidemiological studies than the determination of individual chemicals in human samples.

Keywords: Biomarkers; Exposure assessment; Xenoestrogens; Endocrine disruption


Chemiluminescence detection of superoxide anion release and superoxide dismutase activity: modulation effect of Pulsatilla chinensis by Dachun Yao; Athanasios G. Vlessidis; Yulan Gou; Xinrong Zhou; Yikai Zhou; Nicholaos P. Evmiridis (pp. 171-177).
A novel flow-injection chemiluminescence-based method has been developed for determination of superoxide dismutase (SOD) activity. An in-vitro superoxide anion generation xanthine/xanthine oxidase stable source was established on line with FIA/CL-detection apparatus, for measuring SOD activity. This method can detect SOD in the linear range of 0.002–2.00 U mL−1 with a detection limit of 0.001 U mL−1. Another method for detection of superoxide anion is based on the luminol–FeCl3 chemiluminescence (CL) reaction. This method was used to evaluate superoxide release and SOD activity in rats treated with the traditional Chinese herb Pulsatilla chinensis, which resulted in high clearance of hepatitis B virus (HBV) after treatment of a hepatitis B patient. Interestingly, we found that treatment with Pulsatilla chinensis can specifically increase superoxide release by liver tissues and, at the same time, slightly increase extracellular SOD (ECSOD) activity in plasma; in particular it can markedly increase MnSOD activity in mitochondria in liver tissue. This work revealed a possible mechanism whereby Pulsatilla chinensis prevents possible infection (for example HBV) by specifically increasing superoxide release in the liver and increasing MnSOD activity to minimize superoxide-mediated toxicity.

Keywords: Superoxide anion; Superoxide dismutase; Pulsatilla chinensis ; Chemiluminescence
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