优化气相色谱法测定生活饮用水中六六六和滴滴涕

目的优化GB/T 5750.9-2006《生活饮用水标准检验方法农药指标》中的气相色谱法测定生活饮用水中六六六(α-666、β-666、γ-666、δ-666)和滴滴涕(ρ,ρ'-DDE、ο,ρ'-DDT、ρ,ρ'-DDD、ρ,ρ'-DDT)含量。方法样品经石油醚萃取浓缩后,经由电子捕获检测器-气相色谱测定α-666、β-666、γ-666、δ-666、ρ,ρ'-DDE、ο,ρ'-DDT、ρ,ρ'-DDD、ρ,ρ'-DDT的含量。结果 8种组分在8 min内全部出峰,各物质在5～100.0μg/L浓度范围内线性关系良好,相关系数均大于0.999,检出限为0.007～0.010μg/L,回收率为85.10%～105.85%,相对标准偏差为0.43%～2.68%。结论该方法分离效果高,灵敏度高,重复性好,准确度高,可以满足实验室条件下水样中六六六和滴滴涕的测定。     

QuEChERS方法在茶叶农药残留检测中的应用研究进展

茶叶的农药残留检测关系到茶叶的质量安全。茶叶样品基质复杂,干扰物质多,其样品前处理是农药残留检测过程中耗时最长、工作量最大的部分,并决定分析方法的准确度和精密度。QuEChERs(quick,easy,cheap,effective,rugged,safe)方法作为一种农药多残留分析的前处理方法,由于具有快速、简单、廉价、有效、可靠、安全的特点而成为近年来的研究热点。本文在简要介绍QuEChERS方法的基础上,综述了该方法在茶叶农药残留检测中的重要应用,详细评述了在取样量选择、样品预处理方法、提取剂选择及净化过程等方面对QuEChERS方法进行优化改进的研究进展。分析了QuEChERs方法在茶叶农药残留检测中存在的问题和不足,展望了该方法在茶叶农药残留检测中的发展方向,以期为QuEChERs方法在茶叶农药残留检测中的完善和发展提供参考。     

QuEChERS 方法在茶叶农药残留检测中的应用研究进展

茶叶的农药残留检测关系到茶叶的质量安全。茶叶样品基质复杂,干扰物质多,其样品前处理是农药残留检测过程中耗时最长、工作量最大的部分,前处理技术的好坏也决定着分析的准确性和精密度。QuEChERS(quick, easy, cheap, effective, rugged, safe)方法作为一种农药多残留分析的前处理方法,由于具有快速、简单、廉价、有效、可靠、安全的特点而成为近年来的研究热点。本文就QuEChERS方法及其在茶叶农药残留检测中的应用研究进展进行评述。     

宜昌茶叶中农药残留监测及分析

目的监测茶叶农药残留情况,了解宜昌茶叶质量安全现状。方法采集的样品经过Qu ECh ERS方法进行提取、净化,采用气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)对宜昌市茶叶主产区125批次茶叶样品中25种农药残留进行监测分析,外标法定量。结果所有监测样品中,农药检出39批次,涉及农药6种,检出率31.2%。结论按照GB 2763-2017标准,所检出样品没有超标样品。国家标准缺乏茶叶中部分农药残留最大限量标准,需要进一步完善。     

2009年大连市部分食品中化学污染物监测分析

目的了解大连市部分食品中重金属、有机磷及氨基甲酸酯农药残留、有机氯及菊酯农药残留以及环己基氨基磺酸钠的污染现状,对食品安全进行有效控制。方法按GB/T 5009—2003《食品卫生检验方法理化部分》检测铅、镉、汞、有机氯及菊酯农药残留、环己基氨基磺酸钠、有机磷及氨基甲酸酯农药残留。结果 39份样品中铅超标5份;镉和汞无超标样品。50份蔬菜样品中检出毒死蜱农药残留1份,超标1份;氯氰菊酯农药残留2份,超标1份。10份茶叶样品中检出联苯菊酯农药残留1份,无超标样品。有机磷及氨基甲酸酯农药、有机氯及菊酯农药、环己基氨基磺酸钠均无检出。结论大连市部分水产品中铅含量较高,污染较明显。需要进一步加强监测,控制污染。农药残留水平较低,只在个别蔬菜和茶叶中有不同程度的检出。     

2006-2007年福建省地产茶叶中有机氯农药残留调查

目的了解福建省地产茶叶中有机氯农药残留现状。方法2006-2007年在福建省主要产茶地随机抽取不同品种茶叶共72份,参照GB/T5009.19—2003《食品中六六六、滴滴涕残留量的测定方法》,采用毛细管气相色谱法进行检测。结果所测72份茶叶中,六六六残留量合格率为95.8%;滴滴涕残留量合格率为63.9%。六六六的主要残留成分为γ-HCH,滴滴涕的主要残留成分为p,p′-DDE。闽南地区的有机氯农药残留远高于闽北地区。结论福建省地产茶叶中有机氯农药残留状况不容乐观,应引起重视,加强监管。     

茶叶中农药残留分析技术研究进展

查阅近些年国内外公开发表的文献,简述了我国茶叶生产上常用农药情况,比较了国内外茶叶农药残留最大限量标准,综述了茶叶中农药残留的主要检测技术,重点对固相微萃取法、液相微萃取法、分散固相萃取法等样品前处理技术,以及气相色谱法、液相色谱法、质谱法、免疫分析法等检测技术在茶叶农药残留分析中的应用及特点进行了总结,并对其发展方向进行了展望,以期为今后开展茶叶中农药残留的分析研究提供参考。     

茶叶中农药残留检测方法研究进展

茶叶中农药残留问题受到越来越多的关注,现代仪器分析技术在农残检测中的应用也在不断创新。本文主要综述了茶叶中农药残留检测方法的研究状况,对茶叶中农残检测样品前处理方法和检测技术进行了分析和比较。目前茶叶中农药残留检测方法主要有气相色谱法(gas chromatography,GC)、高效液相色谱法(high performance liquid chromatography,HPLC)、色谱-质谱联用法和酶联免疫吸附测定法(enzyme-linked immunosorbent assay,ELISA)。本文分析了不同检测方法使用的局限性和优越性,为不同性质的茶叶样品农残检测方法的选择提供了依据,旨在为茶叶中农药残留检测新方法的研究提供理论参考。     

杭州市茶园空气中有机农药的调查

茶叶品质与茶园环境密切相关,本文对龙井茶的主产区——杭州市的几个茶园空气中的有机农药残留量进行了调查,结果显示:个别茶园空气中有机农药残留量较高;5种有机磷农药的残留量较低,但检出率高达100%,可能会对茶叶造成污染。从农药残留量来看,2004年空气质量优于2003年,这与茶叶样品的检测结果相符。通过对茶园环境的控制,可以提高龙井茶的品质。     

市售茶叶中30种农药残留与风险评估

本次研究主要为了解30种农药在茶叶中残留状况并对检测结果进行风险评估。随机采购茶叶390份,参考GB 2763-2016对30种农药进行检测,并采用@riskv7.6风险评估软件对检测值进行拟合处理,同时结合点评估和@risk概率评估法评价其膳食暴露风险。结果表明390份茶叶中,农药中检出率最高的为联苯菊酯,高达39.2%。关于样本茶叶中多种农药联用的问题,48%的样品中未检出农药残留。其中203份茶叶中存在农药残留,114份样品中存在2种及以上农药残留情况。所有农药残留水平的95%拟合位点值均能满足GB 2763-2016要求,但有3种不能满足欧盟标准要求。只有一个茶叶的草甘膦检测值超出了GB 2763-2016要求。所检茶叶样品风险评估水平均处在可接受的水平,但甲氰菊酯的急性风险熵处于较高水平。     

Tracking residual organochlorine pesticides (OCPs) in green,herbal, and black tea leaves and infusions of commercially available tea products marketed in Poland

The content of residual organochlorine pesticides (OCPs) was examined in green, herbal, and black tea leaves as well as in their infusions prepared from tea products marketed in the main supermarkets in Poland. It was found that the detected mean levels of organochlorine residues in tea leaves ranged from ?1 dry weight. Among hexachlorocyclohexane isomers, γ-HCH in green tea occurred in the highest concentrations. Among dichlorodiphenyltrichloroethane (DDT) metabolites the highest level of p,p′DDT (1.96 ng g^?1 dw) was in green tea samples. The transfer of OCPs from tea leaves to brew was investigated. The present study revealed that during the infusion process, a significant percentage of the residues, particularly pesticides with high water solubility, were transferred to the infusions. The obtained results show that the percentage transfer of each pesticides from tea to the tea infusions ranged from 6.74% (heptachlor) to 86.6% (endrin). The detected residues were below current MRLs for these pesticides.     

Organochlorine pesticide residues in cow's milk from a tropical region of Mexico

A monitoring study was conducted to assess the magnitude of DDT [(1,1,1-trichloro-2,2-bis( p -chlorophenyl)ethane)] and HCH (hexachlorocyclohexane) contamination of bovine milk from the central tropical region of Mexico as the chemicals are extensively used in livestock and public-health programmes. Among pesticide residues analysed, the milk samples collected from Tlalixcoyan showed a mean level of γ-HCH (0.128 mg kg -1 ), which was significantly higher than residues in milk samples from Medellin (0.049 mg kg -1 ) and Paso San Juan (0.022 mg kg -1 ). The mean level of pp '-DDE in Medellin samples (0.039 mg kg -1 ) was significantly higher than in Paso San Juan (0.018 mg kg -1 ) and Tlalixcoyan (0.024 mg kg -1 ) milk samples. The pp '-DDT mean level from Medellin milk samples (0.089 mg kg -1 ) was significantly higher than the levels detected in the other two areas. The highest mean Σ-DDT level detected in Medellin samples (0.146 mg kg -1 ) was three times the FAO/WHO tolerance level. The highest acceptable daily intakes calculated for Σ-DDT were 0.017 μg kg -1 bw day -1 for adults and 0.530 μg kg -1 bw day -1 for infants; for γ-HCH residues, they were 0.021 μg kg -1 bw day -1 for adults and 0.666 μg kg -1 bw day -1 for infants, indicating that infants are more exposed to pesticide residues. Results indicate that cattle exposure to HCH and DDT results in high levels in dairy milk and a potential health risk for consumers.     

Residues of DDT and HCH in wheat samples collected from different states of India and their dietary exposure: A multicentre study

Under a multicentre study conducted by the Indian Council of Medical Research, 1712 samples of wheat grain/flour were collected from urban and rural areas in 11 states representing different geographical regions of India. These samples were analysed for residues of DDT (2,2-bis (p-chlorophenyl)-1,1,1-trichloro ethane) and different isomers of HCH (1,2,3,4,5,6-hexachloro cyclohexane, a mixture of isomers) by gas-liquid chromatography. Residues of DDT were detected in 59.4% of 1080 samples of wheat grain and in 78.2% of 632 samples of wheat flour. Different isomers of HCH were present in about 45-80% of the samples of wheat grain/flour. Medians of DDT and total HCH, respectively, for pooled samples of wheat grain were 0.013 and 0.035 mg kg^-1, while those for wheat flour were 0.01 and 0.02 mg kg^-1. Estimated daily intakes of DDT and different isomers of HCH through the consumption of wheat contaminated at their median and 90th percentiles constituted a small proportion of their acceptable daily intakes. Amongst the pesticide residues analysed, statutory maximum residue limits have been fixed only for γ-HCH in wheat in India, as 0.1 mg kg^-1 in wheat grain and zero in wheat flour. Residue levels of γ-HCH exceeded these maximum residue limits in five of 1080 samples of wheat grain and in 340 of 632 samples of wheat flour. The failure to meet the requirement of the γ-HCH maximum residue limit in large number of wheat flour samples was attributed to the fixation of practically unachievable zero limit. Comparing the previous studies and the present one, the levels of residues of DDT and HCH in wheat were significantly decreased.     

Pesticide residues in black tea

Summary An investigation of residues of organochlorine and organophosphorous pesticides, as well as of a number of fungicides and of inorganic bromide in 99 samples of black tea taken on the Danish market is reported. The type of pesticide residues involved appear to be very uniform within each country of origin, whereas there are distinct differences between individual countries. Tea from Sri Lanka seems to contain less and fewer residues than tea from the other big tea producing countries. A great many of the samples contained -HCH, lindane and DDT. The use of -HCH and DDT is prohibited in Denmark. Only few other pesticides were detected and at a much lower frequency. None of the teas contained residues that may be regarded as being injurious to health.

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Pesticidrückstände im schwarzen Tee

Zusammenfassung Es wird über Rückstände chlorund phosphorhaltiger Pesticiden, einer Reihe von Fungiciden sowie von anorganischem Bromid in rund 100 Proben schwarzem Tee, entnommen auf dem dänischen Markt, berichtet. Die Art der Pesticidrückstände scheint innerhalb des einzelnen Ursprunglandes sehr einheitlich zu sein, während zwischen verschiedenen Ländern deutliche Unterschiede bestehen. Tee aus Sri Lanka scheint geringere und weniger Rückstände zu haben, als Tee aus anderen großen Herstellungsländern. In einem großen Teil der Proben wurde -HCH, Lindan und DDT festgestellt. Die Anwendung von -HCH und DDT ist in Dänemark verboten. Es wurden nur wenige andere Pesticide festgestellt und mit bedeutend geringerer Häufigkeit. Keiner der Tees wies Rückstände auf, die als gesundheitsschädlich bezeichnet werden können.

     

Pesticide residues in black tea

An investigation of residues of organochlorine and organophosphorous pesticides, as well as of a number of fungicides and of inorganic bromide in 99 samples of black tea taken on the Danish market is reported. The type of pesticide residues involved appear to be very uniform within each country of origin, whereas there are distinct differences between individual countries. Tea from Sri Lanka seems to contain less and fewer residues than tea from the other big tea producing countries. A great many of the samples contained alpha-HCH, lindane and DDT. The use of alpha-HCH and DDT is prohibited in Denmark. Only few other pesticides were detected and at a much lower frequency. None of the teas contained residues that may be regarded as being injurious to health.     

Analysis of contaminated milk with organochlorine pesticide residues using gas chromatography

Milk and milk products are considered to have tremendous nutritional values as they contain a good proportion of protein, fats, and important minerals. However, the nutritional value of the milk produced in Pakistan is not up to the mark as extensive use of pesticides on crops resulted in contamination of milk. Consumption of contaminated food such as milk, meat, fish, eggs can induce increased proportion of organochlorine pesticides in the body. The purpose of this study is to determine organochlorine pesticide residues in milk and their toxicity level by Maximum Residues Level (MRL) values. In the current study, organochlorines such as Dichlorodiphenyltrichloroethane (DDT), Dichlorodiphenyldichloroethane (DDE), Dieldrin, Gamma-hexachlorocyclohexane (?-HCH) also known as Lindane, α-Endosulphan, β-Endosulphan and Endosulphan sulphate were detected with the help of gas chromatograph equipped with electron detector. These pesticides were confirmed by using gas chromatography-mass spectrometry (GC-MS). Analysis of variance is applied (ANOVA) to determine variations of pesticides in all milk samples. Analysis showed non-significant results (p > 0.05) with large variation among all milk samples regarding pesticide residues. The mean values of DDT, DDE were found to be below the MRL value. The mean values of Dieldrin, ?-HCH were also below MRL value. On the other hand mean values of α-Endosulphan, β-Endosulphan, and Endosulphan sulphate were slightly higher than MRL in few milk points. The present study showed large variations of pesticides residues present in milk samples.     

Dietary exposure to organochlorine pesticide residues of the Hong Kong adult population from a total diet study

Dietary exposure of the Hong Kong adult population to organochlorine pesticide (OCP) residues was estimated using a total diet study (TDS) approach. OCPs listed under the Stockholm Convention as persistent organic pollutants (POPs) including, aldrin, dieldrin, chlordane, chlordecone, dichlorodiphenyltricholroethane (DDT), endosulfan, endrin, heptachlor, hexachlorobenzene (HCB), α-hexachlorocyclohexanes (HCH), β-HCH, lindane, mirex, pentachlorobenzene and toxaphene, were studied. Out of 600 composite samples, 55% contained one or more OCP residues at detectable levels. The most commonly detected OCP was DDT (32% of all composite samples), followed by HCB (30%) and endosulfan (22%). The lower- and upper-bound mean exposure estimates of OCP residues ranged from 0% to 0.5% and were 0.1–8.4% of their respective health-based guidance values (HBGVs). The lower- and upper-bound 95th percentile exposure estimates ranged from 0% to 1.2% and were 0.1–13.6% of their respective HBGVs. This indicated that dietary exposures to the OCP residues analysed would be unlikely to pose unacceptable health risks to Hong Kong adults.     

信阳茶叶农药残留检测及其风险评估

目的 了解信阳地区茶叶农药残留情况及其风险程度,以期为信阳地区茶叶质量安全监测提供依据。方法 2013-2020年8年来连续收集信阳地区茶叶样品132个,依据收集年份GB2763对茶叶中农药残留规定,在同一年按照国家标准、农业行业标准等规定的农药测定方法进行测定。运用危害物风险系数法进行农残风险评估。结果 在132个信阳茶叶样品中,检测出农药残留样品100个,农残检出率为75.76%,共检测到农药种类19种,农残超标率为0。通过危害物风险系数评估显示,噻虫啉、唑虫酰胺、呋虫胺存在高度风险。结论 信阳茶叶农药残留检出率较高,但其含量均在均在国家标准所规定的限量值内,整体处于安全水平。从出现后一直存在的6种农药噻虫嗪、丁醚脲、联苯菊酯、氯氟氰菊酯和高效氯氟氰菊酯、氯氰菊酯和高效氯氰菊酯、啶虫脒以及3种存在高度风险的噻虫啉、唑虫酰胺、呋虫胺的需要重点监测。