Organochlorine pesticides in colostrums in case of normal and preterm labor (IASI, Romania)

Assessment of organochlorine pesticides (OCPs) in human body is important for human health because they have weak estrogenic or antiestrogenic effects and are considered endocrine disrupters. We used colostrum of women as indicator for levels of OCPs in human body for mothers with normal and preterm labor from eastern part of Romania. Sixty- three samples of colostrum were extracted by solid-phase extraction. Analyses were carried out using gas chromatography coupled to mass spectrometry (GC-MS). OCPs have been detected in all samples, with p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE) and γ-hexachlorocyclohexane (γ-HCH) being at the highest concentrations. Of the organochlorines measured in clostrum samples from women in preterm labor, median levels of DDTs (470 ng/g) and HCHs (99 ng/g) were higher than for the same compounds from women in normal labor (median of DDTs = 268 ng/g and median of HCHs = 96 ng/g). Normal labor had higher median concentrations of HCB (19.5 ng/g) versus preterm labor (14 ng/g). Statistical data show high Spearman correlation coefficients between various OCPs. We found a good correlation between α-, γ-, β- and δ- HCH isomers (p < 0.001) for both normal and preterm labor. The most abundant target compound was p,p’-DDE (median value 96 ng/g, and 137 ng/g for mother with normal and preterm labor, respectively) in all colostrum samples. The estimated daily intakes of HCHs by infants exceeded corresponding Health Canada guidelines.     

应用拟三元体系相图法制备烟嘧磺隆微乳剂

介绍了通过绘制烟嘧磺隆／表面活性剂,正丁醇／水拟三元体系相图,制备烟嘧磺隆水基化微乳剂的方法。从表面活性剂筛选入手,对阴离子、非离子表面活性剂复配,确定了水基化微乳液的配方,研究了水质、热贮、冷贮对制剂稳定性的影响,同时进行了流变性及高效液相测定原药含量等实验,分析原药分解率。该方法获得的烟嘧磺隆水基化微乳剂,具有成本低,质量稳定,使用环保、安全,市场前景看好等特点,社会、经济效益显著。     

程序升温-电子捕获气相色谱法测定地下水中有机氯农药

对程序升温-电子捕获气相色谱进样温度、进样压力和分流程序进行优化,建立地下水中有机氯农药高灵敏度检测方法。与传统的分流/不分流分析方法相比,该方法将进样体积由1μL增加到30μL,仪器检测限由2.0 ng/L降低到0.1 ng/L。同时减少样品取样量和有机溶剂用量,缩短样品前处理时间,提高分析效率,节省分析成本,有利于全国地下水大批量地质调查样品的分析工作。     

Chemical contaminants, health indicators, and reproductive biomarker responses in fish from the Colorado River and its tributaries

Common carp (Cyprinus carpio), black bass (Micropterus spp.), and channel catfish (Ictalurus punctatus) were collected from 14 sites in the Colorado River Basin (CRB) to document spatial trends in accumulative contaminants, health indicators, and reproductive biomarkers. Organochlorine residues, 2,3,7,8-tetrachlorodibenzo-p-dioxin-like activity (TCDD-EQ), and elemental contaminants were measured in composite samples of whole fish, grouped by species and gender, from each site. Selenium (Se) and mercury (Hg) concentrations in fish were elevated throughout the CRB, and pesticide concentrations were greatest in fish from agricultural areas in the Lower Colorado River and Gila River. Selenium concentrations exceeded toxicity thresholds for fish (>1.0 microg/g ww) at all CRB sites except the Gila River at Hayden, Arizona. Mercury concentrations were elevated (>0.1 microg/g ww) in fish from the Yampa River at Lay, Colorado; the Green River at Ouray National Wildlife Refuge (NWR), Utah and San Rafael, Utah; the San Juan River at Hogback Diversion, New Mexico; and the Colorado River at Gold Bar Canyon, Utah, Needles, California, and Imperial Dam, Arizona. Concentrations of p,p'-DDE were relatively high in fish from the Gila River at Arlington, Arizona (>1.0 microg/g ww) and Phoenix, Arizona (>0.5 microg/g ww). Concentrations of other formerly used pesticides including toxaphene, total chlordanes, and dieldrin were also greatest at these two sites but did not exceed toxicity thresholds. Currently used pesticides such as Dacthal, endosulfan, gamma-HCH, and methoxychlor were also greatest in fish from the Gila River downstream of Phoenix. Total polychlorinated biphenyls (PCBs; >0.11 microg/g ww) and TCDD-EQs (>5 pg/g ww) exceeded wildlife guidelines in fish from the Gila River at Phoenix. Hepatic ethoxyresorufin O-deethylase (EROD) activity was also relatively high in carp from the Gila River at Phoenix and in bass from the Green River at Ouray NWR. Fish from some sites showed evidence of contaminant exposure as indicated by fish health indicators and reproductive biomarker results. Multiple health indicators including altered body and organ weights and high health assessment index scores may be associated with elevated Se concentrations in fish from the Colorado River at Loma, Colorado and Needles. Although grossly visible external or internal lesions were found on most fish from some sites, histopathological analysis determined many of these to be inflammatory responses associated with parasites. Edema, exophthalmos, and cataracts were noted in fish from sites with elevated Se concentrations. Intersex fish were found at seven of 14 sites and included smallmouth bass (M. dolomieu), largemouth bass (M. salmoides), catfish, and carp and may indicate exposure to endocrine disrupting compounds. A high proportion of smallmouth bass from the Yampa River at Lay (70%) was intersex but the cause of this condition is unknown. Male carp, bass, and catfish with low concentrations of vitellogenin were common in the CRB. Comparatively high vitellogenin concentrations (>0.2 mg/mL) were measured in male bass from the Green River at Ouray NWR and the Colorado River at Imperial Dam and indicate exposure to estrogenic or anti-androgenic chemicals. Anomalous reproductive biomarkers including low GSI and gonadal abnormalities (calcifications, edema, and parasites) observed in fish downstream of Phoenix are likely related to the poor water-quality of the Gila River in this area.     

拟除虫菊酯类农药在农产品中的污染现状及减除技术研究进展

拟除虫菊酯类农药因其稳定性和高效性被广泛应用于农业生产中,在农产品中的残留问题日益突出,对食品安全构成威胁。农药残留问题越来越受到消费者和相关研究人员的重视。因此,了解农产品中拟除虫菊酯类农药的污染现状,寻求有效措施控制污染已迫在眉睫。本文介绍了拟除虫菊酯类农药的特性,阐述了全球农产品中拟除虫菊酯类农药的残留现状,同时概述了拟除虫菊酯类农药的减除技术,并对其减除技术发展进行展望,为减少农产品中拟除虫菊酯类农药的残留,保障农产品安全提供参考依据。     

QuEChERS-HPLC-Q-TOF/MS快速筛查蔬菜中32种农药残留

建立了QuEChERS-高效液相色谱-四极杆-飞行时间质谱法用于蔬菜中32种农药残留的快速筛查与确证分析方法。乙睛为提取剂,氯化钠盐析,C18和PSA为净化剂,电喷雾正离子扫描。通过TOF MS-IDA-MS/MS扫描模式,一次采集即可同时获得农药分子的一级精确质量数和二级质谱图信息。在线性范围内32种化合物线性关系良好,相关系数均大于0.9990,在三个加标水平(1,4和20 LOQ)下的平均回收率为70.41%~103.1%,相对标准偏差为1.2%~11.2%,方法检出限LOD为0.3~1.3μg/kg,定量限LOQ为1.0~4.0μg/kg。与国标相比,大大缩短前处理时间;此外,该方法中吡虫啉、虫酰肼等9种农药的方法检出限得到了有效降低;除乙霉威和嘧菌酯回收率略低,其它30种农药回收率均无明显差别。该方法简单快速、高效准确、灵敏度高,能够快速筛查和分析蔬菜中残留农药。     

Quality of plant products from organic agriculture

During the last decade, consumers' trust in food quality has decreased drastically, mainly because of growing ecological awareness and several food scandals (e.g. BSE, dioxins, bacterial contamination). It has been found that intensive conventional agriculture can introduce contaminants into the food chain. Consumers have started to look for safer and better controlled foods produced in more environmentally friendly, authentic and local systems. Organically produced foods are widely believed to satisfy the above demands, leading to lower environmental impacts and higher nutritive values. So far, studies have partly confirmed this opinion. Organic crops contain fewer nitrates, nitrites and pesticide residues but, as a rule, more dry matter, vitamin C, phenolic compounds, essential amino acids and total sugars than conventional crops. Organic crops also contain statistically more mineral compounds and usually have better sensory and long‐term storage qualities. However, there are also some negatives: plants cultivated in organic systems generally have 20% lower yields than conventionally produced crops. Several important problems need to be addressed in the coming years: environmental, bacterial and fungal contamination of organic crops and, the most essential issue, the impact of organic food consumption on animal and human health. Copyright © 2007 Society of Chemical Industry     

浓缩苹果汁中农药残留去除方法的研究现状及展望

农药残留是影响我国苹果浓缩汁质量的关键问题。文中综述了我国浓缩苹果汁中的农药残留状况,指出浓缩苹果汁中常见的农药残留是有机磷杀虫剂,通过对浓缩苹果汁中农药残留方法研究进展的追踪,包括物理方法、化学方法以及微生物方法,对未来该领域的发展进行了展望。     

Assessment of PCDD/F,PCB, OCP and BPA dietary exposure of non-breast-fed European infants

The aim of this study is to obtain data on the exposure of non-breast-fed infants to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), polychlorinated biphenyls (PCB), organochlorine pesticides (OCP), and bisphenol A (BPA) and its chlorinated derivatives through consumption of commercial infant foods with largest shares of the market in 22 European Union countries. The E-Screen bioassay was employed to assess the oestrogenicity of the baby foods and the ethoxyresorufin-O-deethylase (EROD) induction was measured to determine the levels of PCDD/F and PCB. Consequently, the highest total effective xenoestrogen burden (TEXB) of 73.60?pM?Eeq?g^?1 was found in the soy-based formula and the EROD bioassay was always below the limit of quantification (LOQ) (3.5?pg?g^?1). Overall, the estimated dietary exposure to BPA via commercial baby foods was lower than the tolerable daily intake (TDI) of 50?µg?kg^?1 body weight (bw). Furthermore, the findings indicated that the dietary exposure of 0–9-month-old infants through the products investigated here does not exceed the maximum TDI of 4?pg WHO-TEQ (toxic equivalents)?kg^?1 bw. However, exposure to more than 2?pg WHO-TEQ?kg^?1?bw?day^?1 might occur for 0–4-month-old infants consuming ‘starting’ hypoallergenic formula. Moreover, analysis of OCP indicated that the dietary exposure of non-breast-fed infants was not harmful. Considering the importance of early development and the vulnerability of infants and children, it is essential to determine their dietary exposure to contaminants in order to decide which efforts of risk reduction should receive highest priority.