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Analytical and Bioanalytical Chemistry (v.357, #8)
Federation of European Chemical Societies (FECS) Division of Analytical Chemistry (DAC)
by Robert Kellner; Bauke te Nijenhuis (pp. 1011-1012).
A contribution to the ecology and enology of platinum by F. Alt; H. R. Eschnauer; B. Mergler; J. Messerschmidt; G. Tölg (pp. 1013-1019).
Since the introduction of the catalytic cleaning of vehicle exhaust gases, platinum is discussed as environmentally relevant element. Results of such investigations are compared with “natural” platinum background concentrations, which were determined in selected environmental and biological samples. Wine serves as an example for the following the path of platinum, beginning with the uptake during the plant growth, continuing with the fermentation process of grape juice and resulting in the final product.
SI-traceable values for cadmium concentration in the water samples of IMEP-6 by I. Papadakis; P. D. P. Taylor; P. D. Bièvre (pp. 1020-1023).
The certification measurement for the cadmium concentration in the samples as performed by Isotope Dilution (ID) using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is described in framework of the International Measurement Evaluation Programme (IMEP). By using a primary method of measurement (ID), making up a full uncertainty budget and using a sensitive technique (ICP-MS), reference values traceable to SI can be obtained for this material.The uncertainty budget is performed in accordance with the ISO and EURACHEM guides on uncertainty. A comparison is made with certification results of other experienced laboratories also using primary methods where possible.
Validation of three atomic absorption spectrometric methods for the determination of selenium – a comparative evaluation of performance characteristics by R. Allabashi; J. Rendl; M. Grasserbauer (pp. 1024-1028).
Three AAS-methods for the determination of selenium at trace levels were validated and compared on the basis of their performance characteristics. It was observed that the sensitivity of determination of selenium increases from ET-AAS over FI-HG-AAS to HG-ET-AAS by a factor of 40, respectively 100. Moreover HG-ET-AAS exhibits extremely low detection limits enabling the determination of selenium in the ng/l-range. On the basis of recovery experiments, calibration by standard addition and analyses of reference materials matrix effects were not only evaluated (ET-AAS) but also eliminated (FI-HG-AAS).
Development of bovine muscle, liver and urine reference materials for zeranol – preparation, homogeneity and stability by M. O’Keeffe; A. Nugent; A. Cadogan; J. P. Hopkins; E. Daeseleire; C. van Peteghem (pp. 1029-1034).
Samples of bovine muscle, liver and urine, zeranol-free (RM 508, RM 509 and RM 510, respectively) and zeranol-containing (RM 511, RM 512 and RM 513, respectively) were prepared and tested as candidate reference materials. Preliminary studies on achievement of target zeranol content, intercomparison of analytical methods (HPLC-RIA and GC-MS) and effects of lyophilisation and irradiation on zeranol content are described. The preparation of the materials and testing for homogeneity and stability of zeranol in the materials are discussed. The coefficients of variation for zeranol determinations for between-vial homogeneity (4.0%, 4.4% and 4.6% for muscle, liver and urine, respectively) are similar to those for the analytical method (4.0%, 7.3% and 6.8% for muscle, liver and urine, respectively) indicating that the materials are homogeneous. Stability data over a 12-month storage period at temperatures ranging from −18 °C to +37 °C indicate that the materials are sufficiently stable for use as reference materials. This paper is dedicated to the memory of Dr Hilary Stevenson (The Queen’s University of Belfast/DANI) who, together with Mr. W. Graham, facilitated the irradiation of the lyophilised materials.-->
Certification of an animal feed reference material for the organochlorine pesticide contents: BCR CRM 115 by L. G. M. T. Tuinstra; A. H. Roos; B. Griepink; E. A. Maier (pp. 1035-1041).
An animal feed reference material has been prepared and enriched with 15 organochlorine pesticides at levels close to the maximum residue limits set up in the European Directive 74/63/EEC. The homogeneity of the material has been assessed on the basis of the pesticide contents at a level of sample intake of 5 g. The one year stability study revealed an instability of heptachlor, o,p′-DDT, p,p′-DDT, α-HCH and γ-HCH (decrease in content) and p,p′-TDE (increase) at +37 °C; at +20 °C no instability could be demonstrated. The material has been certified in an interlaboratory certification study for: HCB (0.0194 mg/kg), β-HCH (0.023 mg/kg), γ-HCH (0.0218 mg/kg), heptachlor (0.019 mg/kg), γ-Chlordane (0.048 mg/kg), α-Endosulfan (0.046 mg/kg), Dieldrin (0.018 mg/kg), Endrin (0.046 mg/kg), o,p′-DDT (0.046 mg/kg) and p,p′-DDE (0.047 mg/kg). The α-HCH isomer, Aldrin, β-Heptachloro-epoxide, p,p′-DDT and p,p′-TDE could not be certified. The methods used for the certification are described as well as the major difficulties encountered in the study.
Multielement analysis by total reflection X-ray fluorescence spectrometry for the certification of lichen research material by M. Schmeling; F. Alt; R. Klockenkämper; D. Klockow (pp. 1042-1044).
Total reflection X-ray fluorescence spectrometry was applied for the certification of IAEA lichen-336. The elements Ca, Mn, Fe, Cu, Zn, Rb, Sr and Pb were determined simultaneously. The concentrations range from 1.8 mg/kg for Rb to 2360 mg/kg for Ca. The results were compared with those of other methods and laboratories having participated in this certification for the International Atomic Energy Agency (IAEA): emission spectrometry, mass spectrometry, atomic absorption spectrometry, X-ray spectrometry, neutron activation analysis and voltammetry. The results determined by TXRF are in good agreement with the overall means of accepted values and differ from the means by 1 to 10%.
Gas-permeation continuous flow coulometric analysis: determination of sulphur dioxide by S. Liu; Han-xi Shen; Jian-xing Feng; Matthieu Tubino (pp. 1045-1049).
A gas permeation system using two gaseous streams flowing on both sides of a membrane is developed. This gas permeation device and a coulometric detector are adapted for the continuous measurement of relatively high concentrations of sulphur dioxide. The interferences of other gases (NO2, NO and CO2) can be eliminated by using a scrubber behind the gas permeation device in the acceptor stream. The effects of the donor flow rates and gas pressure as well as the membrane thickness on the signal are discussed. The relative standard deviation is 1.3% (n=7) for 2.002×10-3 mol/mol certified sulphur dioxide.
Cr(III)/Cr(VI) speciation in aerosol particles by extractive separation and thermal ionization isotope dilution mass spectrometry by R. Nusko; K. G. Heumann (pp. 1050-1055).
An isotope dilution mass spectrometric (IDMS) method, using the formation of positive thermal ions, was developed for Cr(III) and Cr(VI) speciation in aerosol particles. Cr(III) and Cr(VI) spike species, enriched in 53Cr, were applied for the isotope dilution step. After leaching of filter collected aerosol samples by an alkaline solution at pH 13, species separation was carried out by extraction with a liquid anion exchanger in methyl isobutyl ketone. Cr(VI) in the organic phase was re-extracted into an ammoniacal solution and chromium was then isolated from both fractions of species by electrodeposition. Detection limits of 30 pg/m3 for Cr(III) and of 8 pg/m3 for Cr(VI) were achieved in atmospheric aerosols for volumes of air samples of about 120 m3. These low detection limits allowed the determination of chromium species in continental aerosol particles in dependence on different seasons. The Cr(III) /Cr(VI) ratio was always found to be about 0.3 whereas dust from soil erosion, which is probably the primary source of chromium in the atmosphere, showed higher ratios. This indicates that chromium is oxidized in the atmosphere. The accuracy of the method was demonstrated in two interlaboratory comparisons of Cr(VI) determinations in welding dust samples. The IDMS method also contributed to the certification of a corresponding standard reference material organized by the Standard Reference Bureau of the European Union. Chromium speciation, including the determination of elemental chromium Cr(0), was carried out in aerosols of different welding processes for stainless steel. These analyses showed distinct differences in the distribution of chromium species in the welding process and can be used as an exact calibration method for routine methods in this important field of monitoring corresponding working places.
Simultaneous determination of metal ion concentrations in binary mixtures with a multi-LED photometer by P. C. Hauser; Thusitha W. T. Rupasinghe (pp. 1056-1060).
A compact photometer is based on up to seven different light-emitting diodes whose light is guided into a photometric cell by means of a fibre-optic coupler. The wavelength is selected by switching on the appropriate light source. The application of this multi-wavelength photometer to the determination of binary metal ion samples is demonstrated using model mixtures. Solutions of Fe, Co, Cu, Ni, Cr and Mn were used in combination with several photometric reagents. It was found that the instrument yielded concentration measurements which were usually within a few percent of the correct concentration. These results are comparable to reported data obtained with conventional instruments for similar measurements. The application of the instrument for simultaneous determination in flow-injection analysis employing rapid computer controlled switching of the light-emitting diodes is also demonstrated. A limitation in the use of light-emitting diodes for the simultaneous determination was found to arise from the fact that in some instances non-linear calibration curves are obtained when employing light-emitting diodes as light sources. This occurs when the absorptivity of the measured compound changes over the emission band of the diodes. Multiple regression analysis is then not easily possible.
The composition analysis of YBa2Cu3O7-δ or PrBa2Cu3O7-δ thin films and (YBa2Cu3O7-δ/PrBa2Cu3O7-δ)n heterostructures prepared by CVD by C. Dubourdieu; N. Didier; O. Thomas; J. P. Sénateur; N. Valignat; Y. Rebane; T. Kouznetsova; A. Gaskov; J. Hartmann; B. Stritzker (pp. 1061-1065).
Some YBa2Cu3O7-δ films and heterostructures prepared by Chemical Vapor Deposition (CVD) were analyzed in our laboratories by EPMA-EDX or WDX, RBS, SNMS and AES. It was found that in some cases the results of composition analysis can significantly deviate from each other. At least two main reasons for these deviations exist: the different lateral resolution and the application of different reference samples for the calibration.
In-line flow injection extraction-preconcentration through a passive hydrophilic membrane. Determination of total phenols in oil by flow-injection analysis by J. F. van Staden; H. E. Britz (pp. 1066-1071).
An in-line flow injection extraction-preconcentration procedure for the determination of total phenols in oil is described. The reaction between phenolic compounds and 4-aminoantipyrine in the presence of K2S2O8 as oxidizing reagent was used. The phenols were extracted and preconcentrated from a xylene solution by using a more selective passive hydrophilic Spectrapor membrane which also removed interferences. The phenols deprotonated after diffusion to the basic acceptor stream and the preconcentrated phenolate was injected into a carrier stream containing 4-aminoantipyrine as colour reagent. The carrier stream then merged with the oxidant stream, followed by detection at 500 nm. The system was suitable for the determination of total phenols in oil at a sampling rate of 12 samples per hour with an RSD of better than 1.3%. The detection limit was 0.09 mg/l for phenol, 0.18 mg/l for o-cresol and 0.02 mg/l for m-cresol. The results of the proposed system compared favourably with a standard manual 4-AAP method and a standard GC procedure.
Rapid resolution of five polynuclear aromatic compounds in a mixture by derivative non-linear variable-angle synchronous fluorescence spectrometry by Y. Q. Li; Xian Zhi Huang (pp. 1072-1075).
A combination of non-linear variable-angle synchronous fluorescence spectrometry with the derivative technique has been developed. A rapid simultaneous identification and quantitative determination of acenaphthene, carbazole, anthracene, 9,10-dimethylanthracene and perylene were achieved from a single spectrum by non-linear variable-angle synchronous fluorescence and combined derivative non-linear variable-angle synchronous fluorescence. The latter approach offered a further improvement in spectral resolution and analytical sensitivity. The usefulness of the proposed method was confirmed by adding known amounts of these five polynuclear aromatic compounds to the extract of waste water samples.
Results of collaborative trials concerning the analysis of benzo-a-pyrene in creosote by E. Anklam; Markus Lipp; Anne Müller; Jan Van Eijk; Marc Van Leemput; Guy Van Steertegem (pp. 1076-1080).
The results of five collaborative studies concerning the analysis of benzo-a-pyrene (BaP) in creosote by high-performance liquid chromatography (HPLC) are presented. Six to twelve laboratories participated in these studies over a time period of three years. These studies were carried out in order to evaluate the method which is described in the CEN standard ENV 1014-3. The concentrations of BaP in creosote samples analysed were in the range of 20 ppm to 550 ppm. Whereas the values for repeatability (5–10%) were acceptable in nearly all collaborative trials, those for reproducibility have improved significantly in the last study (23–33%). For the previous four collaborative trials the reasons for the relatively poor reproducibility values, especially for analytes containing low concentrations of BaP, could be detected. They were mainly based on problems with chromatographic separation and with integration. The method described in ENV 1014-3 has been proven to be suitable for the determination of the BaP content in creosote.
Group separation of ortho-PCBs, coplanar non-ortho-PCBs and PCDDs/PCDFs using an alumina column as an one-step clean-up procedure by R. Loos; S. Vollmuth; R. Niessner (pp. 1081-1087).
A novel, simple inexpensive and rapid clean-up procedure is presented for the separation and quantitative determination of polychlorinated biphenyls (ortho-PCBs), coplanar non-ortho-PCBs (PCB No. 77, 126, 169) and polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in environmental samples. This clean-up procedure is the first method separating ortho-PCBs, non-ortho-PCBs and PCDD/PCDFs in one step with a single activated alumina column. Firstly, the ortho-PCBs are eluted from the activated alumina with a non-polar solvent. The non-ortho-PCBs are isolated in the second fraction with a more polar solvent-mixture, and finally the PCDD/PCDFs are collected in a polar fraction. This clean-up procedure was used to determine the congener-specific concentrations of ortho-PCBs, non-ortho-PCBs 77, 126 and 169 and PCDD/PCDFs in two different seepage waters and in one sewage sludge by HRGC and HRMS. The toxic equivalent quantities (TEQs) of the individual PCDD/PCDF-congeners and some toxic coplanar PCB-congeners were estimated.
Ultraviolet absorption spectra of all 209 polychlorinated biphenyls evaluated by principal component analysis by P. L. Andersson; Peter Haglund; Mats Tysklind (pp. 1088-1092).
The ultraviolet absorption spectra of all 209 polychlorinated biphenyls (PCBs) were recorded in the range 200–300 nm and displayed two important absorption maxima, viz., the main-band, λmax 200–225 nm, and the κ-band, λmax 245–265 nm. By utilising principal component analysis, substitution related spectral characteristics of the PCBs, underlying the main patterns of the spectra, were examined. Captured in the multivariate evaluation were e.g., the importance of chlorine atoms in ortho positions, determining the intensity and existence of the κ-band, chlorine substitution in para-para position, and the total number of chlorine atoms. The measured UV-spectra of all 209 polychlorinated biphenyls provide important physico-chemical descriptors for use in future quantitative structure-activity and structure-property relationship (QSAR/QSPR) studies.
Cyclodextrin-based optosensor for the determination of quinine by Zhilong Gong; Z. Zhang (pp. 1093-1096).
A flow-through optosensor for quinine is described. It has been developed in conjunction with a flow-injection analysis system and uses immobilized β-cyclodextrin as the sensing agent. The detection limit for quinine was 0.20 ng ml-1 with a relative standard deviation of 2.1% for the determination of 0.05 μg ml-1 (n=7) of quinine. The method has been successfully tested for the determination of quinine in some pharmaceutical preparations.
An optosensor for tryptophan with C18 silica gel as a substrate by Zhilong Gong; Z. Zhang (pp. 1097-1100).
A flow-through optosensor for tryptophan with C18 silica gel as a substrate is proposed. It has been developed in conjunction with a flow-injection analysis system and is based on the retention of tryptophan on the C18 column and the enhancement of its fluorescence. The detection limit is 25 ng mL-1 with a relative standard deviation of 2.9% for 7 determinations of 10 μg mL-1 of tryptophan. Most of the common species do not interfere. The method has been successfully applied to a pharmaceutical preparation.
Preparation of a piezoelectric immunosensor for the detection of Salmonella paratyphi A by immobilization of antibodies on electropolymerized films by Shihui Si; Fenglian Ren; Wen Cheng; Shouzhuo Yao (pp. 1101-1105).
To obtain new coatings for the preparation of piezoelectric immunosensors, the anodic polymerization of o-aminophenol (oAP), o-phenylenediamine (oPD) and m-phenylenediamine (mPD) onto a gold-plated crystal has been studied. The possibility of immobilizing an antibody (anti-S. paratyphi A) onto the crystal via the electropolymerized films was investigated. The poly-mPD film gave the best results for immobilizing the antibody. With antibodies crosslinked on the poly-mPD film, a piezoelectric immuno-assay for the detection of S. paratyphi A was proposed. The shift (ΔF=F20s−F400s, Hz) between the frequency at 20 s after the addition of sample (F20s), and that of 400 s (F400s) was used to construct a calibration graph, and shortening of the assay time was achieved. The S. paratyphi A concentration in the range of 105–109 cells/ml can be measured by this method.
Determination of bromine and iodine in biological and environmental materials using epithermal neutron activation analysis by Xiaolin Hou; Chifang Chai; Qinfang Qian; Chunsheng Li; Ke Wang (pp. 1106-1110).
Epithermal neutron activation analysis (ENAA) was applied to the determination of the contents of bromine and iodine in 40 biological and environmental standard reference materials and Chinese diets. Boron nitride (BN) for solid samples and BN+Cd for liquid samples were adopted as shield material. Irradiation was carried out in inner and outer irradiation sites in a Miniature Source Reactor (MNSR) for solid and liquid samples, respectively. The 443 keV photopeak of 128I and the 616 keV photopeak of 80Br were used. The precision of measurement (relative standard deviation) is 2∼6% for contents of iodine of more than 100 ng/g and 8∼12% in the 20∼100 ng/g range in solid samples, and 12∼18% at less than 100 ng/ml in liquid samples. For bromine, the precision of measurement is 2–8% for solid samples and lower than 13% for liquid samples. The detection limits under experimental conditions varied between 10∼30 ng/g, 55∼95 ng/g and 25∼68 ng/g for iodine and 50∼150 ng/g, 200∼450 ng/g and 100∼300 ng/g for bromine in ENAA with BN shield in inner irradiation sites, with Cd shield and BN+Cd shield in outer irradiation sites, respectively.
Optimized microwave preparation procedure for the elemental analysis of aquatic sediment by X. Wen; Lingzheng Wu; Y. Zhang; Yang Chu (pp. 1111-1115).
This paper summarizes several key points in applying the microwave preparation technique to the elemental analysis of aquatic sediments and reports systematic experiments in searching for an optimal microwave preparation procedure for element analysis in sediment samples. The determination of the elements Cu, Pb and Cd in a standard reference aquatic sediment sample (CRM 280, COMEUR) was achieved by first digesting the samples in a microwave oven equipped with PFA advanced composite vessels, followed by AAS measurement. The influence of microwave power, digestion time, various dissolution reagents and the HF removing conditions was studied. It has been shown that for a 0.1 g sediment sample the optimal microwave preparation conditions are: 4–5ml HNO3/HF/H2O2 as solvent, digesting time 30 min with 100% microwave power and evaporating the residual acid within 8 min in an open vessel at 80 °C. The element recovery rates with AAS measurement can reach up to 92.4–100.6%.
Application of microwave digestion to the preparation of sediment samples for arsenic speciation by C. Demesmay; Micheline Ollé (pp. 1116-1121).
Several extraction procedures are described allowing arsenic speciation in sediments. The extraction of organometallic compounds such as dimethylarsinic acid or monomethylarsonic acid is quite simple since these compounds are stable in the different extraction media (HCl/ HNO3, H3PO4, ammonium oxalate) and are easily released independent of the extraction mode (magnetic stirring or microwave solubilization). Extraction yields are higher than 96% for these two arsenic forms. An HCl/HNO3 microwave solubilization procedure allows the quantitative solubilization of mineral arsenic, but the differentiation between the two oxidation states is not possible owing to the oxidation of As(III) to As(V). Extractions with orthophosphoric acid or ammonium oxalate allow the solubilization of mineral arsenic with extraction yields ranging from 90 to 95% and the differentiation between As(III) and As(V). Nevertheless, the amount of As(III) is underestimated owing to its partial oxidation. The usefulness and advantages of microwave solubilization compared with conventional extraction procedures are discussed.
Inductively coupled plasma mass spectrometry for the sequential determination of trace metals in sea water after electrothermal vaporization of their dithiocarbamate complexes in methyl isobutyl ketone by Sri Juari Santosa; S. Tanaka; Kazuo Yamanaka (pp. 1122-1127).
A sensitive method has been developed for the sequential determination of V, Mn, Fe, Co, Ni, Cu, Zn, Mo and Sb in sea water using inductively coupled plasma mass spectrometry (ICP-MS) after electrothermal vaporization of their dithiocarbamate complexes in methyl isobutyl ketone (MIBK). After complexion with sodium diethyldithiocarbamate (NaDDTC), all trace analyte elements were simultaneously separated from sea water matrix and concentrated 20 fold in a single extract of MIBK, followed by introduction of 10 μL of the extract into argon plasma using a pyrolytic graphite rod electrothermal vaporizer (ETV). Sensitivity enhancement due to chemical modification using a mixed modifier of Pd(NO3)2-Mg(NO3)2 was observed for all the elements. The limits of detection ranged from 2 ng/L for Co to 329 ng/L for V. For replicate determinations of the elements in sea water, the repeatability was within 10% (as a coefficient variation), except for V (12.8%). The recovery test performed on a sea water sample resulted in a range value from 87% for Sb to 119% for V. The method has been successfully applied to sea water samples collected from the surface to the depth of 5000 m at a sampling station in the northwest Pacific Ocean.
Supercritical fluid extraction of polycyclic aromatic hydrocarbons (PAH) from native soil and fly ash with pure and modified carbon dioxide and dimethylether by B. W. Wenclawiak; Thomas Paschke; Martin Krappe (pp. 1128-1132).
Polycyclic aromatic hydrocarbons (PAH) and alkyl-PAH in the lower mg/kg range were extracted from soil and fly ash. Extraction yields were measured for toluene Soxhlet, supercritical carbon dioxide, toluene modified carbon dioxide, and toluene modified dimethylether (DME) extractions. Pure DME similarly to toluene Soxhlet extraction enhances extraction yields (32 mg/kg) as compared to pure carbon dioxide (21 mg/kg). In particular, higher molecular weight PAH are extracted with pure DME. 5% Toluene modified carbon dioxide (43 mg/kg) and toluene modified DME (50 mg/kg) yield much better extraction yields than Soxhlet (32 mg/kg) or pure supercritical fluid extractions.
Improved screening analysis of organic pollutants in river water samples by gas chromatography with atomic emission detection (GC-MIP-AED) by Helmut Frischenschlager; Michael Peck; Christian Mittermayr; E. Rosenberg; Manfred Grasserbauer (pp. 1133-1141).
The potential of gas chromatography with a microwave-induced plasma atomic emission detector (GC-MIP-AED) for the screening analysis of trace organic components in river water samples is presented. The application of a commercially available GC-MIP-AED system to the screening of organic trace compounds has been greatly enhanced by the optimisation of the operating parameters to achieve the highest sensitivity for the simultaneous determination of C, H, Cl, Br, S and N. An improved evaluation of the chromatographic data has been carried out using several new self-developed macros, which allow the calculation of elemental response ratio factors (RRFs) and empirical formulas for the analysed compounds at different concentration levels. A significant dependence of the RRFs on the concentration level was found for hydrogen and sulphur, whereas the dependence of the RRFs on the type of compound is not significant, considering the analytical objective. Limits of detection in the pg-range can be obtained for the elements investigated. The calculation of empirical formulas and its precision is shown for several analytes over a wide range of concentration. At a concentration level close to the limit of detection the error of the formula calculation increases significantly. The performance characteristics of the GC-MIP-AED system in the presence of matrix interferences are assessed by measuring spiked river water samples.
Chemical analysis of rain and snow samples from Chernogolovk/Russia by IC, TXRF and ICP–MS by P. Hoffmann; V. K. Karandashev; T. Sinner; H. M. Ortner (pp. 1142-1148).
Data are reported for a first measurement campaign for a great number of cations (the range of concentrations for main components is given in ng/mL: Na:<70–880; Mg: 12–160; Al:<7–120; K: 200–1600; NH4 +: 2500–9000; Ca: 300–2500; Fe:<140–1200; Zn: 20–320) and anions (HCOO-: 100–1800; CH3COO-: 400–14500; C2O2- 4: <100–460; NO- 2: <20–55; NO- 3: 660–9900; SO2- 3:<100–1150; SO4 2-: 450–19700; Cl-: 170–3200) in rain and snow samples of the Chernogolovka region 80 km northeast of the centre of Moscow. These data serve as a first assessment of the situation of the atmosphere in this region. For the determination of fluoride, formate, acetate, nitrite, bromide, nitrate, sulfite, and sulfate by IC, a relevant development of the method was carried out. For some metallic cations, a critical quality control was achieved by parallel measurements with ICP-MS, TXRF, and IC. Furthermore, time resolved measurements were performed for a rain event. Filtration experiments were undertaken to differentiate between the presence of a series of elements and species in liquid or solid state in the collected aqueous samples.
Measurement of lead isotope ratios in wine by ICP-MS and its applications to the determination of lead concentration by isotope dilution by S. Augagneur; B. Medina; F. Grousset (pp. 1149-1152).
Methods are described for the accurate and precise determination of lead concentrations and the isotopic composition of lead in wine samples using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This method needs little sample preparation. A comparison with lead isotope ratios measured by Thermal Ionization Mass Spectrometry (TIMS) in three wine samples reveals a good agreement between the two techniques. The lead concentration in three certified wine samples were measured by isotope dilution (ID) and the results are compared with those obtained by external calibration ICP-MS.
Colorimetric determination of iron in infant fortified formulas by sequential injection analysis by A. N. Araújo; Joan Gracia; Jose´ L. F. C. Lima; Manel Poch; M. Lu´cia M. F. S. Saraiva (pp. 1153-1156).
A procedure is described for the colorimetric determination of iron in infant fortified formulas based on sequential injection analysis (SIA). Iron(III) complexation with thiocyanate is used as colour developing reaction. The system enables the determination of iron in the samples (after digestion by dry ashing and treatment with 0.2 mol/L nitric acid in the range of 0.50–20.0 mg/L, consuming 140 μL of the sample and 8 mg thiocyanate per determination. The reactor geometry and the adjustment of the ionic content of the calibration solutions is important for the accuracy of the results. A regression line according to the equation [Fe(III) (mg/L)]SIA=−0.3(±0.4)+1.03(±0.04) [Fe(III) (mg/L)]FAAS was obtained after comparative analysis of a set of 12 samples. The measurement rate was 34 s, thus allowing to analyze 100 samples per hour with a relative standard deviation lower than 2%.
Platinum determination in nutrient plants by inductively coupled plasma mass spectrometry with special respect to the hafnium oxide interference by S. Lustig; S. Zang; B. Michalke; P. Schramel; W. Beck (pp. 1157-1163).
Platinum, emitted from automobile exhaust catalysts, is mainly oxidised in a humic soil, as described previously [1]. An experiment with nutrient plants was carried out to elucidate the bioavailability and accumulation of these platinum containing species. The plants [Allium cepa L. (Weiß, Frühling), Rephanus sativus L. (Riesenbutter), Vicia faba L. (Hedin, Herzfreya), Zea mays L. (Delis) and Solanum tuberosum L. (Selma)] were grown under natural conditions. For mass balances all ways of platinum transport into and out of the system were monitored during the growing period. Plants growing in untreated soil took up less than 1% of the platinum naturally present in the soil [0.15±0.11 μg kg-1 (78%)]. Plants growing in soil treated with a platinum containing tunnel dust took up slightly more platinum. The comparison of ICPquadrupole-MS results with those obtained by a double focusing magnetic sector ICP-MS showed a strong dependence of the platinum concentration on the Hf-content in the sample. An evaluation method for the correction of the Hf-influence for ICP-quadrupole-MS is presented.
Use of C-18 reverse-phase cartridges for estimation of metal complexation by a residue from olive oil industry by E. Díaz-Barrientos; M. Bejarano; L. Madrid (pp. 1164-1167).
Formation of complexes between Cu and organic polymers present in olive mill wastewater (OMW) is shown to be a cause of metal solubilization by the residue, using C-18 reverse-phase cartridges (RPC) for separating the complexed metal. Nearly 100% of the metal released from a polluted river sediment by OMW solutions is retained by the cartridges. The proportion of Cu retained by the cartridges is somewhat lower (50–80%), if the OMW solution initially contains Cu. About 70–80% of Cu released by OMW from a soil column previously loaded with high doses of metal is also retained by the cartridges. Incomplete Cu retentions are not thought to be due to a lack of efficiency of RPC in immobilizing Cu complexes, but to the formation of an equilibrium between free and complexed forms of the metal.
Determination of acetaldehyde in liquid, solid and semi-solid food after pervaporation-derivatization by I. Papaefstathiou; U. Bilitewski; M. D. Luque de Castro (pp. 1168-1173).
A spectrophotometric method for the determination of acetaldehyde in liquid, semi-solid and solid food samples, employing the coupling of a continuous flow configuration to a pervaporation unit, has been proposed. It is based on the reaction of the analyte with fuchsin in acidic medium and subsequent formation of a coloured product (alkylsulphonic acid chromophore) with sodium sulphite, which was monitored spectrophotometrically. Variable sensitivity was obtained by altering the pervaporation temperature and the thickness of the membrane. The detection limits went down to 4.2 μg/mL and the precision was between 1.2 and 3.6%.
Sensitive spectrophotometric determination of ascorbic acid in fruit juices and pharmaceutical formulations using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP) by Sérgio L. C. Ferreira; Marcus L. S. F. Bandeira; Valfredo A. Lemos; Hilda C. dos Santos; A. C. Spinola Costa; Djane S. de Jesus (pp. 1174-1178).
A simple and very sensitive method has been developed for the determination of ascorbic acid based on the oxidation of ascorbic acid to dehydroascorbic acid by iron(III), followed by a complexation of iron(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol(Br-PADAP). The iron(II) complex is formed immediately, with absorption maxima at 560 and 748 nm and a molar absorptivity of 1.31 × 105 l mole–1cm–1 and 5.69 × 104 l mole–1cm–1, respectively. The ascorbic acid determination is possible with a linear range up to 2.4 μg ml–1, a calibration sensitivity of 0.744 ml μg–1 at 560 nm and 0.323 ml μg–1 at 748 nm, and a detection limit of 15 ng ml–1 and 44 ng ml–1, respectively. The procedure was used for the ascorbic acid determination in several fruit juices and pharmaceutical formulations. The results demonstrated a good precision (R.S.D. < 1%) and are in agreement with those obtained with others methods. The Br-PADAP method proposed is six times more sensitive than the method using the iron(II)-1,10-phenanthroline system.
Determination of diazepam and otilonium bromide in pharmaceuticals by ratio-spectra derivative spectrophotometry by Basilio Morelli (pp. 1179-1184).
Binary mixtures of diazepam and otilonium bromide are analyzed by ratio-spectra first- and second-derivative spectrophotometry. The procedures are accurate, non-destructive and do not require any separation step. Calibration graphs are linear with zero-intercept up to 50 μg/ml, r ranging from 0.9996 to 0.9999. Working wavelengths in the first- and second-derivative mode, respectively, are: diazepam 247 nm and 231 nm, otilonium bromide 262 nm and 226 nm. Limits of detection (LOD) are 0.30 and 0.12 μg/ml for diazepam and 0.063 and 0.30 μg/ml for otilonium bromide. The methods were successfully applied for determining the two drugs in laboratory mixtures and in pharmaceutical products.
Boron determination in biological materials by inductively coupled plasma atomic emission and mass spectrometry: effects of sample dissolution methods by A. M. S. Nyomora; R. N. Sah; P. H. Brown; R. O. Miller (pp. 1185-1191).
This study compares four sample dissolution methods for Boron determination in two National Institute of Standard and Technology (NIST) botanical Standard Reference Materials (SRMs) and three Agriculture Canada/NIST RMs, each having a reference (certified or best estimate) B concentration. The dissolution treatments consisted of: 1) dry ashing at 500° C, 2) wet digestion with HNO3 + H2O2, 3) extraction with hot HNO3 and 4) closed vessel microwave dissolution. The samples were spiked before and after imposing dissolution treatments to study B recovery by inductively coupled plasma mass spectrometric (ICP-MS) analysis. Microwave digests of NIST SRM 1515 and some in-house RMs were also used to compare the B values of ICP-MS and ICP-AES (atomic emission spectrometry). While all three digestion methods (dry ashing, wet ashing and microwave) dissolved botanical samples, only the microwave method worked well for animal tissues. In terms of B values in these materials, there was no significant difference among the three digestion treatments. Near 100% recovery of B spiked before and after the sample dissolution indicates that there may not be a significant loss of B during the dissolution process used in this study. Extraction with hot HNO3 was as effective as the three digestion treatments, and B values for this method agreed well with reference values. For the botanical materials studied, the B values determined by ICP-AES were not significantly different from ICP-MS values. This study shows that a simple, time and labor efficient hot HNO3 extraction is as effective as other digestion/dissolution methods for quantitative B recovery from biological materials.
Microwave digestion and matrix separation for the determination of cadmium in urine samples by electrothermal atomization atomic absorption spectrometry using a fast temperature program by Shiow-Ching Chen; Meei-Yun Shiue; M.-H. Yang (pp. 1192-1197).
A method is proposed which involves sample pretreatment followed by electrothermal atomic absorption spectrometry (ETAAS) for determination of cadmium in human urine. A microwave digestion system was devised to accommodate double-closed vessels for simultaneous digestion of batches of up to 24 urine samples in about 20 min. After digestion, matrix substances which might interfere were removed using silica-immobilized 8-hydroxyquinoline (I-8HOQ) columns. The analyte adsorbed on the column was then eluted with dilute nitric acid solution and determined by ETAAS using a fast temperature program. Neither ashing steps in the furnace heating program nor use of matrix modifiers was necessary. The accuracy, precision, limit of detection, and sample throughput of the method were evaluated. With meticulous control of systematic errors which may be introduced in the pretreatment procedures, the present method can serve as a reference technique for the analysis of Cd in urine samples.
Detection of estradiol and testosterone in hair of cattle by HPL/EIA by A. Gleixner; Heinrich H. D. Meyer (pp. 1198-1201).
This study concerns the detection of natural steroid hormones in hair of cattle. Estradiol (E2) and testosterone (T) were chosen as representatives of estrogens and androgens. In particular, the influence of age, sex and hair pigmentation on the steroid concentrations was investigated. Samples were obtained from numerous steers, cows, bulls, and female and male calves. The extraction procedure for E2 and T from hair comprised liquid-liquid and solid-phase extraction and was followed by an essential high-performance liquid chromatography (HPLC) step for further purification of the extracts. Final quantification was performed with specific enzyme immunoassays (EIA). Lower E2-concentrations were detected in the hair of some steers, cows, and bulls (approximately 1 ng/g), in several of these hair samples the concentrations of E2 were below the limit of detection. Testosterone was measured in the hair of steers (approximately 3 ng/g), cows (approximately 6 ng/g), and bulls (in average 15 ng/g). There was a significant difference in the testosterone concentrations of white (approximately 8 ng/g) and of black hair (approximately 33 ng/g) of bulls. In hair from all male and female calves, E2 and T were measured. The concentrations amounted approximately to 9 ng E2/g and 3 ng T/g for female calves and to 5 ng E2/g and 7 ng T/g for male calves. There was no significant influence of sex or hair colour on the steroid concentrations in hair of calves. The results suggest that the method is a powerful means to detect natural steroid hormones in hair of animal origin.
Screening and simultaneous quantitative measurement of six sulfonylureas in serum by liquid chromatography/mass spectrometry with atmospheric-pressure chemical-ionization (APCI LC/MS) by F. Susanto; H. Reinauer (pp. 1202-1205).
A method is described for the separation, identification and quantification of six sulfonylureas in serum by liquid chromatography/mass spectrometry with atmospheric-pressure chemical-ionization (APCI LC/MS). The sample pretreatment is based on single-step liquid-liquid extraction, using the 4-methylcyclohexyl analogue of glibenclamide as internal standard. Carbutamide and tolbutamide have been chosen as representative sulfonylureas of the first generation and glipizide, glibornuride, glibenclamide and gliquidone as those of the second generation, widely used in the treatment of diabetes mellitus. This method allows a screening of these sulfonylureas in serum and subsequently the quantification of the serum level in one run of measurement. Accuracy, precision, specificity and sensitivity for each sulfonylurea are presented and discussed.
Use of Mycosep multifunctional clean-up columns for the determination of trichothecenes in wheat by electron-capture gas chromatography by J. Weingaertner; R. Krska; W. Praznik; M. Grasserbauer; H. Lew (pp. 1206-1210).
A quick and reliable method is described for the determination of trichothecene mycotoxins employing gas chromatography with electron capture detection. Using the Mycosep® multifunctional clean-up columns the clean-up procedure is reduced to a 1-step extract purification, thus saving considerable time in comparison with classical clean-up methods, without sacrificing the purity of the extract. The method was tested and validated for five trichothecenes (deoxynivalenol, nivalenol, 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol and fusarenon X). In addition, the performance of this new clean-up technique was compared with an already well established method.
Chemical characterization of the black crust present on the stone central portal of St. Denis abbey by G. C. Galletti; Paola Bocchini; Darinn Cam; Giuseppe Chiavari; Rocco Mazzeo (pp. 1211-1214).
A black crust sample from the stony central portal of the abbey of St. Denis, France, was analyzed by chromatographic and spectroscopic techniques to determine whether it was due to atmospheric pollution or to the degradation of a past restoration treatment. Stratigraphic surveys by optical microscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy/energy dispersive X-ray fluorescence (SEM/EDX) and pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) were consistent in ascribing the bulk of the crust to gypsum (CaSO4 ⋅ 2H2O) with inclusion of carbon particulate. The organic fraction was a minor constituent of the black crust. Hence, the deterioration by an organic substance used in the past to restore the building was ruled out.