Analysis of selected mycotoxins by capillary electrophoresis

Summary The separation of the mycotoxins ochratoxin A, ochratoxin B, zearalenone and moniliformin by standard capillary zone electrophoresis (CZE) and cyclodextrins modified CE is described. In addition, reversed electroosmotic flow (EOF) conditions via quarternary ammonium running buffer additives have been briefly examined. Parameters influencing selectivity and mobility as well as spectroscopic properties of the analytes have also been investigated. Separations performed at pH values from 5 to 11 show a marked pH dependency of the mobilities accompanied by pronounced shifts of the UV/VIS and/or fluorescence spectra of the compounds. In general, the on-line recording of spectra by diodearray detection (DAD), proved to be highly versatile for peak tracking simultaneously with the structure elucidation and thus for the optimization of sample introduction, peak resolution and detection conditions.     

环境样品分析

本文是"分析试验室"定期评述"环境样品分析"的第10篇综述。评述了2008年1月至2009年12月间环境样品分析各个方面的进展,主要内容包括:概述,大气、水体、土壤和沉积物、生物样品分析,城市污泥、垃圾堆肥和垃圾渗滤液分析,质量控制、质量保证及不确定度等。引用参考文献1607篇。     

环境样品分析

本文是"分析试验室"定期评述"环境样品分析"的第9篇综述。它全面评述了2006年1月至2007年12月间我国环境样品分析方面的进展,主要内容包括:概述,大气、水体、土壤和沉积物、生物样品、城市污泥、垃圾堆肥和垃圾渗滤液分析等。引用参考文献990篇。     

环境样品分析

本文是“分析试验室”定期评述“环境样品分析”的第8篇综述。它全面评述了2004年1月至2005年12月间我国环境样品分析各个方面的进展，主要内容包括：概述，大气、水体、土壤和沉积物、生物样品分析，质量控制和质量保证等。引用参考文献967篇。     

Analysis of musk fragrances in environmental samples

The methods for the determination of polycyclic and nitro-aromatic musk compounds in comparison to other fragrances such as OTNE ([1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethylnaphthalen-2yl] ethan-1-one) as well as those for the respective metabolites are described in this contribution. It covers instrumental aspects, as well as procedures for extraction and clean-up. Protocols for the determination of musks in water, sludge, biota, and air are summarised and discussed. Extractions by means of solid phase extraction (SPE) and liquid-liquid extraction (LLE) in case of water samples are evaluated for the diverse applications, i.e., wastewater, surface water and seawater. While LLE is preferred for the analysis of bulk for transport studies and for special process studies SPE might be worth the effort. Considering sludge, sediment and biota samples, drying and successive accelerated solvent extraction. Soxhlet extractions as well as cold column extractions are being compared. ASE has proven to be the most exhaustive and quickest to adopt method. Clean-up by means of size exclusion chromatography and silica sorption chromatography with their respective merits and problems are demonstrated. Suggestions for routine and research analysis are also given. The diverse approaches for enantioselective separations are discussed in respect to HHCB, AHTN and the metabolite HHCB-lactone. The power of two-dimensional (GCxGC) approaches is demonstrated considering the various production impurities (isomers) of the two polycyclic musks with the highest usage rates. The usage of tandem mass spectrometry and high resolution mass spectrometry for the same purpose is also discussed. The identification of an isomer of the HHCB-transformation product HHCB-lactone from wastewater treatment that has not been described in the literature before, is presented as well. Additionally some ideas to make the REACh process more efficient are discussed considering the special experiences from the development of the analysis of musk fragrances in the environment.     

Analysis of polychlorinated n-alkanes in environmental samples

Polychlorinated n-alkanes (PCAs), also known as chlorinated paraffins (CPs), are highly complex technical mixtures that contain a huge number of structural isomers, theoretically more than 10,000 diastereomers and enantiomers. As a consequence of their persistence, tendency to bioaccumulation, and widespread and unrestricted use, PCAs have been found in aquatic and terrestrial food webs, even in rural and remote areas. Recently, these compounds have been included in regulatory programs of several international organizations, including the US Environmental Protection Agency and the European Union. Consequently, there is a growing demand for reliable methods with which to analyze PCAs in environmental samples. Here, we review current trends and recent developments in the analysis of PCAs in environmental samples such as air, water, sediment, and biota. Practical aspects of sample preparation, chromatographic separation, and detection are covered, with special emphasis placed on analysis of PCAs using gas chromatography–mass spectrometry. The advantages and limitations of these techniques as well as recent improvements in quantification procedures are discussed.     

Analysis of volatile sesquiterpenoids in environmental and geological samples

In order to evaluate vloatile compounds, especiallly sesquiter-penoids, in environmental and geological samples a method was penoids, in environmental and geological samples a method was required to characterize these components when they occur at low concentrations. After fractionation of the total sample extracts by TLC the aliphatic fractions were analyzed by HRGC AND THE kovats indices of all resolved peaks were calculated and comkpared with indices of all resolved peaks were calculated and compared with those obtained for commercial standards. As final step, the fractions were analyzed by HRGC-MS and structures confirmed by comparison of their mass spectra with those of certified sesuiterpene standards. Additionally sesquiterpenoids present in the dissolved phase in water samples were concentrated by solid phase extraction using XAD-2 resin. In this initial study, recovery tests with the resin were carried out in order to evaluate its performance rather than validating the methodology.     

Quantification of estrogenic mycotoxins at the ng/L level in aqueous environmental samples using deuterated internal standards

Because of their pronounced estrogenicity, resorcyclic acid lactones (RALs) are of concern in aqueous environments even at the low ng/L level. Therefore, we developed an accurate, precise and sensitive HPLC-MS/MS method to detect these mycotoxins in different aqueous environmental samples. The compounds investigated included zearalenone (ZON), alpha- and beta-zearalenol, zearalanone as well as alpha- and beta-zearalanol. The use of isotope labelled internal standards (in this case deuterated RAL-analogues) ensured an accurate quantification of the target analytes, independent of matrix compounds interfering with the analytes during ionisation and analyte losses occurring during sample preparation. Sample enrichment was carried out by solid-phase extraction (SPE) using Supelclean Envi-18 cartridges. Absolute method recoveries for all analytes ranged from 95 to 108%, 70 to 102%, and 76 to 109%, method detection limits from 0.5 to 2.1 ng/L, 0.4 to 1.1 ng/L, and 0.8 to 12.4 ng/L and precision from 3 to 14%, 2 to 13% and 4 to 16% in drainage water, river water and wastewater treatment plant (WWTP) effluent, respectively. The method was applied to verify the emission of RALs from a Fusarium graminearum infested crop field into the drainage system. Zearalenone was present in drainage water in concentrations up to 30 ng/L. So far, none of the other five investigated compounds have been detected.     

食品中真菌毒素样品前处理方法的研究进展

真菌毒素是由真菌在一定环境条件下产生的一类具有毒性的小分子次级代谢产物。真菌毒素种类多,毒性强,污染范围广,可经食物链直接或间接进入人体,危及人体健康。食品基质形态多样,成分复杂,而实际样品中真菌毒素含量低,难以直接对目标物进行分析,故高效的样品前处理技术能实现待测物的分离和富集,在实际样品的分析中尤为重要。该文主要综述了基于磁性纳米材料、石墨烯类材料、分子印迹材料、免疫亲和材料、适配体功能材料等新型分离介质的液相萃取技术、固相萃取技术、场辅助提取技术(磁性固相萃取、超声辅助提取、微波辅助提取)、免疫亲和柱法、QuEChERS法等前处理技术在食品中真菌毒素分析中的应用,并对其分析的发展趋势进行了展望。     

Analysis of emerging organic contaminants in environmental solid samples

Spreading sewage sludge on agricultural lands has been actively promoted by national authorities as an economic way of recycling. However, as by-product of wastewater treatment, sewage sludge may contain toxic substances, which could be incorporated into agricultural products or be distributed in the environment. Moreover, sediments can be contaminated by the discharge of wastewater effluents into rivers. This article reviews the determination of emerging contaminants (surfactants, flame retardants, pharmaceuticals and personal care products) in environmental solid samples (sludge, soil and sediment). Sample preparation, including extraction and clean-up, as well as the subsequent instrumental determination of contaminants are discussed. Recent applications of extraction techniques, such as Soxhlet extraction, ultrasound assisted extraction, pressurised liquid extraction, microwave assisted extraction and matrix solid-phase dispersion to the analysis of emerging contaminants in environmental solid samples are reviewed. Determination of these contaminants, generally carried out by gas chromatography and liquid chromatography coupled with different detectors, especially mass spectrometry for the identification and quantification of residues, is also summarised and discussed.      

Analysis of fenvalerate in its formulations and environmental samples using spectrophotometry

Two rapid, simple, sensitive, and nonextractive spectrophotometric methods were described for the determination of fenvalerate (syntheitic pyrethroid) in its formulations, water and grain samples. The methods are based on the hydrolysis of fenvalerate with methanolic NaOH to form 3-phenoxybenzaldehyde. The resultant aldehyde group was condensed with 4-aminoantipyrine in the basic medium to form a red product having λ_max at 489 nm or condensed with4,4′-methylene-bis-m-nitroaniline to form a plae red product with an absorption maximum of 513 nm. Beer’s law was obeyed over the range 0.6–10 μg/mL (molar absorptivity 2.184 × 10⁴ L/mol cm) for 4-aminoantityrine and over the range of 1–12 μg/mL (molar absorptivity 4.162 × 10⁴ L/mol cm) for 4,4′-methylene-bis-m-nitroaniline. The formations of color derivatives with the reagents are instantaneous and stable for 40 and 32 h, respectively. The methods were rapid, simple, sensitive, and free from nontarget species. The proposed methods have been applied to the determination of fenvalerate in its formulations and environmental samples. The text was submitted by the authors in English.     

Analysis of radioactive metal ions in environmental and liquid effluent samples

This paper describes the development and validation of analytical procedures for the separation and determination of⁹⁰Sr,⁹⁰Y,²³⁸Pu,^239/240Pu,²⁴¹Am,²⁴¹Cm and^243/244Cm in liquid effluents and environmental samples. The procedures use supported reagents for extraction chromatography (reversed phase partition chromatography) that enable the separation of the analytes from a large number of other radionuclides present.     

Analysis of selenium in environmental and biological samples by neutron activation

This paper presents the results of the application of a fast rabbit system and a high thermal neutron flux to neutron activation analysis of selenium in environmental samples. The short-lived radionuclide^77mSe, (17.5s) is used for analysis. Results are presented for selenium in sea-water and rain-water, in biological reference materials, in food-stuffs and milk powder, in human hair and human blood-serum.     

Analysis of inorganic species in environmental samples by capillary electrophoresis

The use of capillary electrophoresis for the determination of inorganic species in environmental samples is reviewed. Topics covered include the separation of inorganic anions, inorganic cations, transition metal cations and organometals in different environmental matrices, such as atmospheric deposition, atmospheric aerosols, gases, natural waters, waste waters, soil, sediment and marine biological samples. Cited literature is gathered according to the type of matrix, so that the focus is on the discussion of matrix effects rather than on the method development for a single class of compounds. For each matrix, surveyed methods are tabulated in order to assist the method selection. Innovative applications of capillary electrophoresis to advanced environmental research are also emphasised.     

Analysis of poly-beta-hydroxybutyrate in environmental samples by GC-MS/MS

Application of gas chromatography-mass spectrometry (GC-MS) can significantly improve trace analyses of compounds in complex matrices from natural environments compared to gas chromatography only. A GC-MS/MS technique for determination of poly-beta-hydroxybutyrate (PHB), a bacterial storage compound, has been developed and used for analysis of two soils stored for up to 319 d, fresh samples of sewage sludge, as well as a pure culture of Bacillus megaterium. Specific derivatization of beta-hydroxybutyrate (3-OH C4:0) PHB monomer units by N-tert-butyl-dimethylsilyl-N-methyltrifluoracetamide (MTBSTFA) improved chromatographic and mass spectrometric properties of the analyte. The diagnostic fragmentation scheme of the derivates tert-butyldimethylsilyl ester and ether of beta-hydroxybutyric acid (MTBSTFA-HB) essential for the PHB identification was shown. The ion trap MS was used, therefore the scan gave the best sensitivity and with MS/MS the noise decreased, so the S/N was better and also with second fragmentation the amount of ions increased compared to SIM. The detection limit for MTBSTFA-HB by GC-MS/MS was about 10(-13) g microL(-1) of injected volume, while by GC (FID) and GC-MS (scan) it was around 10(-10) g microL(-1) of injected volume. Sensitivity of GC-MS/MS measurements of PHB in arable soil and activated sludge samples was down to 10 pg of PHB g(-1) dry matter. Comparison of MTBSTFA-HB detection in natural soil sample by GC (FID), GC-MS (scan) and by GC-MS/MS demonstrated potentials and limitations of the individual measurement techniques.     

Determination of some selected polycyclic aromatic hydrocarbons in environmental samples by high-performance liquid chromatography with fluorescence detection

Summary Analytical methods for the determination in environmental samples, of some selected Polycyclic Aromatic Hydrocarbons (PAH's), which are included on the EPA Priority Pollutant list, have been developed and evaluated. The methodology involves the extraction of PAH's from water samples by solvent extraction with dichloromethane. Solid samples were ultrasonically extracted with acetone/hexane and the extract was cleaned up on a silica gel/alumina column. The concentrated and cleaned up extracts were analysed by HPLC on a polymeric C₁₈ column using a gradient of acetonitrile/water as the mobile phase and fluorescence detection. Typical detection limits lie in the range of 1–30 ng ml^–1 of the analytes, but after sample pretreatment detection limits of 10–300 ng l^–1 were obtained. The extraction, clean-up and HPLC methodology was applied to the determination of selected PAH's in coal washings samples and the method was validated by the quantification of PAH's in a natural contaminated and a spiked sediment.     

Bismuth-207 in environmental samples

Measurements of fallout 207Bi in environmental samples were reported for water filters used at the Scott Base in Antarctica and the surface soils containing high amount of fallout nuclides. The level of 207Bi in these samples was found to be nearly the same or a little higher than that of fallout 60Co and the 207Bi/137Cs activity ratios were in the range of 0.001-0.018. Contamination of bismuth by 207Bi was found in "high purity" bismuth on market and its level was measured to be 1.9 mBq/g-Bi.