Liquid chromatography study of pyrene degradation by two micromycetes in a freshwater sediment.

Pyrene biodegradation in a freshwater sediment without fungi supply, or inoculated with two sediment micromycetes, Mucor racemosus var. sphaerosporus and Phialophora alba was studied after 0, 5, 13, 28, 60 and 90 days. The influence of glucose addition was estimated, and a liquid chromatographic method for simultaneous quantitative determination of residual anthracene, fluoranthene and pyrene in the sediment was developed. Samples with PAHs were extracted in Soxhlet with ethyl acetate, and LC analysis was performed on a 5 microm Supelcosil column (150 x 4.6 mm I.D.) with gradient elution (2 ml min(-1)) of acetonitrile-water and UV detection at 254 nm. Recoveries of anthracene, fluoranthene and pyrene were 90.3%+/-1.1%, 93.2%+/-0.9% and 90.42%+/-1.9%, respectively, without interference. The native sediment microorganisms (with or without glucose added) have shown 35% pyrene degradation and sediment with glucose inoculated by the strains revealed 40%.     

Cross-sectional biomonitoring study of pesticide exposures in Queensland,Australia, using pooled urine samples

A range of pesticides are available in Australia for use in agricultural and domestic settings to control pests, including organophosphate and pyrethroid insecticides, herbicides, and insect repellents, such as N,N-diethyl-meta-toluamide (DEET). The aim of this study was to provide a cost-effective preliminary assessment of background exposure to a range of pesticides among a convenience sample of Australian residents. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n = 24 pools of 100 specimens). Concentrations of urinary pesticide biomarkers were quantified using solid-phase extraction coupled with isotope dilution high-performance liquid chromatography–tandem mass spectrometry. Geometric mean biomarker concentrations ranged from <0.1 to 36.8 ng/mL for organophosphate insecticides, <0.1 to 5.5 ng/mL for pyrethroid insecticides, and <0.1 to 8.51 ng/mL for all other biomarkers with the exception of the DEET metabolite 3-diethylcarbamoyl benzoic acid (4.23 to 850 ng/mL). We observed no association between age and concentration for most biomarkers measured but noted a “U-shaped” trend for five organophosphate metabolites, with the highest concentrations observed in the youngest and oldest age strata, perhaps related to age-specific differences in behavior or physiology. The fact that concentrations of specific and non-specific metabolites of the organophosphate insecticide chlorpyrifos were higher than reported in USA and Canada may relate to differences in registered applications among countries. Additional biomonitoring programs of the general population and focusing on vulnerable populations would improve the exposure assessment and the monitoring of temporal exposure trends as usage patterns of pesticide products in Australia change over time.     

Simultaneous determination of 2-phenylbenzotriazole-type mutagens, PBTA-1 through -8, in river water by liquid chromatography-tandem mass spectrometry

We describe a method for the simultaneous determination of eight kinds of phenylbenzotriazole-type mutagens (PBTA-1, -2, -3, -4, -5, -6, -7 and -8) in river water based on liquid chromatography-tandem mass spectrometry (LC/MS/MS). The application of dopant-assisted atmospheric pressure photoionization (APPI) for the detection of the PBTAs was studied. The APPI technique provided higher PBTA signal intensities than those obtained with an electrospray ionization (ESI) source, and the APPI method was used for the determination of the PBTAs. A solid-phase extraction procedure was used for the extractions of PBTA-1 through -8 from river water. The procedure was rapid and the relative standard deviations were below 15%. The detection limits of PBTA-1 through -8 in river water using the proposed method were found to range from 0.04 to 0.5 ng L(-1) and PBTAs were successfully detected in river water at sub-ng L(-1) levels.     

用于水中多环芳烃被动采样的聚合物厚度和材料的选择：哪个更有力地影响采样器性能？

本文使用3种单相聚合物制作用于多环芳烃被动采样的装置,这3种聚合物分别为聚甲醛(POM)、硅橡胶(SR)和聚乙烯(PE),通过室内试验测定了它们的分配系数和POM的扩散系数以及验证了动态积累模型。此外,在野外现场对每种装置的性能进行了评估。基于已开发模型的支持,讨论了使用不同材料和聚合物厚度的装置性能。结果表明,采样器性能,比如浓度平均周期的长短和多环芳烃的采集容量,都广受所选材料的影响。采样器的厚度也会对装置的性能造成影响,但程度很小。选择合适的聚合物和/或厚度可以使采样器更有适用于快速平衡或动态积累,以及促进膜或水边界层对动态积累的控制。此外,利用膜技术控制或平衡的化合物能够更精确的被量化,因为它们不需要利用参比法(PRC)来校正。然而,当富集浓度达到平衡后,采样器中的平均浓度就不能准备测量化合物浓度,而由膜控制的采样装置通过动态累积的方式能够提供不需要PRC校正的平均浓度;随着膜传质阻力的提高,采样器的检测限也得到提高。
精选自Angel Belles, Claire Alary, Yannick Mamindy-Pajany.Thickness and material selection of polymeric passive samplers for polycyclic aromatic hydrocarbons in water: which more strongly affects sampler properties?. Environmental Toxicology and Chemistry: Volume 35, Issue 7, pages 1708–1717, July 2016. DOI: 10.1002/etc.3326
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3326/full