Determination of 10 Pyrethroids Pesticide Residues in Rice by GC-MS-MS

[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous magnesium sulfate and sodium chloride, cleaned up by florisil solid phase extraction （SPE） cartridge, and determined by multiple reaction monitoring mode. [Result] The method showed good linearity over the range of 0.010-0.500 mg/L for 10 pyrethroid pesticide with correlation coefficients over 0.99. The detection limits were 0.005 -0.010 mg/kg. The method was validated by analyzing samples spiked with 0.05, 0.10, 0.20 mg/kg of 10 pyrethroid pesticides, respectively. The average recoveries in rice ranged from 75.0-115.5%, and the relative standard deviations （RSD） were between 3.9%-6.9%. [Conclusion] The method is easy, accurate and reliable, which can meet the requirement for the simultaneous determination and confirmation of pyrethroid pesticide residues in rice.

Comparison of Two Procedures for Extraction and Clean-up of Organophosphorus and Pyrethroid Pesticides in Sediment

Two procedures were compared for extraction and clean-up of 20organophosphorus and 19 pyrethroid pesticides in sediment to identify the more effective procedurefor groups of pesticides or individual compounds. In Procedure I, methanol/water and n-hexane wereused for extraction, and 1:10 (v/v) dichloromethane in n-hexane and acetone were used as eluents foreluting the analyte through the cartridge, with one evaporating steps on a rotary evaporator andtwo eluting steps on the cartridge. n-hexane/acetone (2:1, v/v) was used for extraction and elutionin Procedure II with one evaporating step on a rotary evaporator and one eluting step on thecartridge. All extractions were performed under an ultrasonic bath and gas chromatography and massspectrometry were utilized for measurements. Procedure II was developed as a rapid, timesaving, lesscostly and safer substitute for Procedure I which was an old method. Procedure II was moreeffective for almost all the organophosphorus pesticides tested and 11of the 19 pyrethroidpesticides, while Procedure I was more appropriate for analysis of 5 pyrethroid pesticides. However,recoveries of most pyrethroid pesticides were fairly low. Thus, further studies should focus onadjustment and formulation of solvents for more efficient extraction and clean-up of pyrethroidpesticides from sediment samples.

Separation of chlorinated hydrocarbons and organophosphorus, pyrethroid pesticides by silicagel fractionation chromatography and their simultaneous determination by GC-MS

A silicagel fractionation procedure for environmental sample extracts, which separates chlorinated hydrocarbons(CHCs) and organophosphorus, pyrethroid pesticides into two groups for subsequent instrumental analysis, was developed in this study. This method was achieved by optimizing the fraction cut-off volume of elution and different solvents. Using fully activated silica gel and cut-off CHCs collection after 10 ml 10% dichloromethane (DCM) in n-hexane passing through the column resulted in satisfactory separation of CHCs and organophosphorus, pyrethroid pesticides. This procedure had a higher reliability for CHCs than for organophosphorus, pyrethroid pesticides, because there is a relatively reliable recovery for CHCs. This approach is less expensive due to reducing sample pre-treatment time and solvent consumption.

Determination of Organochlorine and Synthetic Pyrethroid Pesticide Residues in Water Samples Collected from Different Locations of Bangladesh

The present study was aimed to validate an analytical method for the quantification of 19 organochlorine and 2 synthetic pyrethroid pesticide residues in water samples using modified quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction and Gas Chromatography coupled with Electron Capture Detector (ECD). The selected pesticide residues were determined by in-house validated method. The analytical method was validated by evaluating the accuracy, precision, linearity, limit of detection (LOD) and limit of quantification (LOQ). The average recoveries of the selected pesticides ranged from 78% to 117% with RSDr ≤ 12% in two fortification levels of 0.02 and 0.1 mg/L. The linearity was ≥0.995 for all of the selected pesticides. The LOD ranged from 0.003 to 0.006 mg/L and the LOQ was 0.02 mg/L for all the selected analytes. This method was applied satisfactorily for the residue analysis of 108 water samples collected from nine districts of Bangladesh. Among the analyzed samples, only 4 had cypermethrin residues (0.026 mg/L, 0.034 mg/L, 0.045 mg/L and 0.05 mg/L). The level of detected cypermethrin residues were above the WHO recommended guide line values of water quality.

A Review of Agricultural Pesticides Use and the Selection for Resistance to Insecticides in Malaria Vectors

Most national malaria control programmes rely extensively on pyrethroid insecticides to control mosquito vectors of this disease. Unfortunately, the intensive use of this class of insecticides both in public health and agriculture has led to its reduced efficacy. The objective of this review was to assess the role of agricultural pesticides use on the development of resistance to insecticides in malaria vectors and the potential impact of this resistance on control activities. We searched library catalogues and public databases for studies that included data on resistance to the major classes of insecticides: organochlorines, carbamates, organophosphates and pyrethroids, in the malaria vectors of Anopheles genera. There is a strong geographical bias in published studies many originating from West African countries. Several studies demonstrate that resistance to pyrethroids is widespread in the major malaria vectors of the Anopheles gambiae and Anopheles funestus complexes. Assessing the impact of insecticide resistance on vector control is complicated owing to the lack of studies into the epidemiological consequences of resistance on the control of malaria and other vector borne diseases.

Ecological and Human Health Risk Assessment of Pesticide Residues in Fish and Sediments from Vea Irrigation Reservoir

The low yield of food production ascribed to harm caused by pests has led to the application of pesticides to food crops. Pesticide residues from the application on crops are mostly found in foods that can cause diseases for consumers of such products. A total of 37 pesticide residues consisting of 15 organochlorines (OC), 13 organophosphorus (OP) and 9 synthetic pyrethroids (SP) were determined. The QuEChERS method was exploited for extraction and clean-up. Gas Chromatograph was used for detection and quantification which was equipped with an electron capture detector and pulse flame photometric detector. The results showed that the mean concentrations of pesticides in fish ranged from 0.007 mg·kg-1 to 1.026 mg·kg-1 for OCs, 0.002 mg·kg-1 to 0.190 mg·kg-1 for OPs and 0.004 mg·kg-1 to 0.032 mg·kg-1 for SP. Sediments have mean concentrations ranged from 0.005 mg·kg-1 to 1.207 mg·kg-1 for OCs. OP ranges from 0.002 mg·kg-1 to 0.399 mg·kg-1 and 0.003 mg·kg-1 to 0.202 mg·kg-1 for synthetic pyrethroids. Maximum Residue Limits were exceeded in both fish and sediment samples except for malathion, fenitrothion, profenofos, gamma-chlordane, and deltamethrin. Exposure in children ranged from 4.60 × 10-6 mg·kg-1·d-1 to 2.36 × 10-3 mg·kg-1·d-1 and in adults it is from 1.97 × 10-6 mg·kg-1·d-1 to 1.01 × 10-3 mg·kg-1·d-1. Health risk estimation revealed a non-cancer risk potential of β-HCH in sediment and aldrin and p,p'-DDE in fish. Carcinogenic risk assessed for organochlorine pesticide residues indicates cancer benchmark concentrations greater than 10-4 to 10-6 threshold for acceptance.

Surveying of Pesticides Commonly on the Markets of Iran in 2009

Considering the potential pesticide side effects on environment, their short and long term untoward effects on living creatures, their excessive usage for producing more agricultural products, and also their application to destroy pests of any sort, the present study was carried out to investigate the used amount of common pesticides in Iran markets. A questionnaire was designed. Referring to pesticide selling shops and plants preservations organizations in Tehran and Isfahan, the sufficient data was collected and then categorized regarding the applications and the total amount of used pesticides in a year. The results demonstrated that there were 60 sorts of used pesticides in Iran. They included Organochlorine (10%), Organophosphorus (28.4%), Pyrethroids derivatives (10%), Carbamate derivatives (10%), and others (41.6%). The commonest pesticide used in a year was Organophosphorus and the least one was Organochlorine. The obtained data pointed out that the most common pesticide was Organophosphorus. Given that Organophosphorine compounds are poisonous in living creatures and cause short and long term side effects. It is recommended that responsible authorities provide the necessary information for the aimed groups in terms of the allowable using amount of pesticides, the protection strategies and the pesticides hazards on users.

安徽省薄壳山核桃产地有机磷和拟除虫菊酯农药残留及风险评估

【目的】调查安徽省薄壳山核桃主产区土壤和果实中有机磷农药和拟除虫菊酯农药残留情况,评估土壤和果实中农药残留风险。【方法】采集安徽省薄壳山核桃主产区土壤和果实样品各13份,分析6种有机磷农药和4种拟除虫菊酯农药的残留,采用风险熵值评估土壤中农药残留的生态风险,采用健康风险评估模型计算果实中农药残留的人体摄入健康风险。【结果】所有土壤样品中均有农药检出,检出浓度范围为n.d.~195.1μg·kg^(-1)(n.d.表示未检出),氯氰菊酯(n.d.~195.1μg·kg^(-1))和甲氰菊酯(n.d.~90.61μg·kg^(-1))检出浓度最高,对硫磷在土壤中检出率为100%,单个土壤样品中最多检出6种农药;果实中仅有一个样品中未检出农药,其他样品中农药检出范围为n.d.~156.3μg·kg^(-1),甲氰菊酯(n.d.~156.3μg·kg^(-1))和氯氰菊酯(n.d.~29.42μg·kg^(-1))检出浓度最高,甲氰菊酯的检出率最高(69.23%),单个果实样品中最多检出4种农药,果实中农药残留浓度均未超过国家标准规定的限量值。土壤中所有农药残留的生态风险介于中等风险和高风险之间,RQ:0.16~2.48(RQ表示生态风险总和)。10种农药的人体健康风险值均小于1,成人摄入果实的健康风险高于儿童。【结论】安徽省薄壳山核桃主产区土壤和果实中存在一定程度的农药残留,土壤中的农药残留存在一定的生态风险,果实中的农药残留不会对人体产生健康风险,研究结果可为安徽省薄壳山核桃的食品安全监管提供参考。

拟除虫菊酯农药类特异性传感体系构建及其在柑橘农残检测中的应用

拟除虫菊酯类农药在我国柑橘等果品中的施用量占全球第一,对其残留的快速筛查和监管对于保障我国果品食用安全具有重要意义。该文研究多功能纳米材料(NaYF_(4)∶Yb,Er-Fe_(3)O_(4)@MIP)的制备条件,采用傅里叶变换红外光谱、透射电子显微镜对该材料进行表征,通过对NaYF_(4)∶Yb,Er-Fe_(3)O_(4)@MIP的吸附和选择性实验,验证了其对4种拟除虫菊酯类农药具有较好的选择性和吸附性能,并构建基于该材料的拟除虫菊酯农药类特异性传感体系对柑橘果品菊酯类农残进行快速检测。结果表明,该传感体系在0.02~2.5 mg/L内对拟除虫菊酯类农药(溴氰菊酯、氯氰菊酯、氟氯氰菊酯、氰戊菊酯)具有良好的线性关系,检出限分别为6.17×10^(-4)、6.65×10^(-4)、7.21×10^(-4)、9.61×10^(-4)、6.43×10^(-4)mg/L。结合柑橘鲜果专属前处理技术进行实际柑橘样品检测,加标回收率为87.9%~105.8%,相对标准偏差为0.53%~6.41%,方法准确、灵敏、稳定,可以用于实际柑橘样品中拟除虫菊酯类农药的检测。

微生物对拟除虫菊酯类农药吸附和降解机制研究进展

近年来,由于高毒有机氯和有机磷农药被禁止使用,拟除虫菊酯类农药(pyrethroids,PYRs)因其高效性和稳定性被广泛应用于农业生产及环境中,但其频繁使用所带来的残留危害也日渐突出。3-苯氧基苯甲酸(3-phenoxybenzoic acid,3-PBA)是PYRs的主要代谢产物之一,为环境雌激素类物质,具有较大的潜在危害性。农药残留严重影响了人们的生产和生活,同时引起了研究人员的广泛关注,PYRs和3-PBA降解菌被大量报道,微生物及其降解酶对农产品和环境中农药残留的去除或减除也是公认的有效方法之一,并且基因工程和分子生物学技术的不断发展为继续深入发掘减除农药残留的方法提供了新途径。本文概述PYRs和3-PBA的基本性质、残留危害,综述PYRs对农产品和环境的残留现状、微生物对PYRs的代谢方式与吸附和降解机制研究进展,并对其降解酶及酶基因工程进行展望,旨为解决农产品和环境中农药残留问题提供参考。

气相色谱-质谱联用检测烟草中拟除虫菊酯类农药残留量的不确定度评定

依据行业标准YC/T 405.3—2011,采用气相色谱-质谱联用对烟草中拟除虫菊酯类农药的残留量进行了不确定度评定,通过建立测量模型,识别和量化实验过程中的不确定度来源,接着对各不确定度分量进行合成和扩展,最终得出6种农药的实际检测结果。结果表明,影响不确定度的主要因素为标准溶液配制、标准曲线拟合,其次为测量重复性和样品制备,回收率对不确定度的影响相对较小;在95.45%置信区间时,取包含因子k=2,烟草中氟氯氰菊酯、氯菊酯、高效氯氟氰菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯的检测结果及扩展不确定度分别为(0.4810±0.0402)、(0.4660±0.0397)、(1.0359±0.1024)、(1.0147±0.1012)、(0.9400±0.0759)、(0.9490±0.0770)mg/kg;标准溶液配制对6种农药引入的不确定度分量贡献率为40%~60%,而样品制备和回收率对6种农药引入的不确定度分量贡献率普遍较低,为2%~9%。为了减小不确定度应该配制合适浓度的标准溶液,优化样品制备过程中的前处理步骤,提高人员的实验操作能力,定期对仪器及量具进行维护。

气相色谱法测定草莓中17种有机氯和拟除虫菊酯类农药残留量

本文建立了气相色谱法(GC)检测草莓中17种有机氯、拟除虫菊酯类农药残留的方法。样品通过乙腈-乙酸(体积比为99∶1)溶液提取,盐析和净化后,经DB-17色谱柱(30.00 m×0.25 mm×0.25μm)分离,气相色谱-电子捕获检测器(GC-ECD)定量检测。结果表明,有机氯、拟除虫菊酯类农药在0.01~1.00μg/mL范围内线性关系良好,相关系数(R2)均在0.9950以上,定量限在0.3~0.9μg/kg;对样品进行0.05 mg/kg、0.10 mg/kg、0.50 mg/kg3个浓度加标回收试验,总加标回收率为88.22%~113.39%,相对标准偏差为0.19%~5.20%,满足方法学要求。该方法简单、快速、准确、经济,适用于草莓中有机氯、拟除虫菊酯类农药的定量分析。

凝胶渗透色谱和气相色谱-质谱法测定动物食品中27种有机氯和15种拟除虫菊酯类农药残留量

A GC-MS method for the determination of 27 organochlorine pesticides and 15 Pyrethroid pesticides in animal food is established.The method was based on Gel Permeation chromatography combined with solid-phase extraction for sample preparation.Rapid qualitative and quantitative analyses was carried out by gas chromatography-mass spectrometry under the selective-ion monitoring mode.The experimental results showed that the correlation coefficients were better than 0.99,the recoveries for spiked standards were 70%-104%,the relative standard deviations were 2.1%-15.9%.

茶鲜叶中3种拟除虫菊酯农药残留量测定的不确定度分析

目的:评定气相色谱法测定茶鲜叶中氯氰菊酯、氰戊菊酯和溴氰菊酯3种拟除虫菊酯农药残留量的不确定度。方法:通过建立数学模型,分析测定过程中的不确定度来源,包括样品测定重复性、标准曲线拟合、添加回收率、标准溶液配制、样品称量和前处理、仪器测定等,并对其进行量化、合成与扩展。结果:在0.10 mg/kg添加水平下,氯氰菊酯、氰戊菊酯、溴氰菊酯的扩展不确定度分别为0.011,0.011,0.012 mg/kg,当置信概率为95%(k=2)时,测定结果可表示为:氯氰菊酯(0.093±0.011) mg/kg,氰戊菊酯(0.094±0.011) mg/kg,溴氰菊酯(0.098±0.012) mg/kg。结论:该方法主要不确定来源为标准溶液配制、标准曲线拟合及回收率,提示样品检测过程中需对这几个方面进行严格控制。

浊点萃取-异辛烷反萃取-气相色谱质谱法测定茶饮料中8种农药残留

目的:快速测定茶饮料中有机氯和拟除虫菊酯类农药残留量.方法:选用非离子表面活性剂聚乙二醇4000(PEGG4000)作为浊点萃取剂,用异辛烷超声反萃取后,取上层异辛烷溶液上机.采用HPG5 msUI毛细管色谱柱对异辛烷溶液进行分离,再经GC/MS进行定性和定量分析.结果:有机氯和拟除虫菊酯类农药分别在0.01~2.0,0.02~4.0mg/L的质量浓度范围内呈良好线性关系,相关系数均大于0.995;方法的检出限为0.003~0.008 mg/kg,定量限为0.01~0.02 mg/kg,平均回收率78.3%~98.4%,相对标准偏差2.7%~8.5%(n=6).结论:该方法操作过程简单,富集率高、实用、安全、经济,适用于茶饮料类液体饮料中的农药多残留的快速测定.

拟除虫菊酯类农药对斑马鱼幼鱼的神经毒性作用研究

目的 探究4种拟除虫菊酯类农药(溴氰菊酯、丙烯菊酯、高效氯氰菊酯、顺式氰戊菊酯)对斑马鱼的神经毒性作用。方法 对4种农药采用静态暴露方法,分析其在高、中、低3种剂量下对斑马鱼幼鱼的形态、神经行为的影响;同时以活性氧(reactive oxygen, ROS)、超氧化物歧化酶(superoxide dismutase, SOD)、乙酰胆碱酯酶(acetylcholinesterase, AchE)为指标,研究各农药在高中低剂量下对斑马鱼幼鱼神经化学的影响。结果 4种拟除虫菊酯类农药均对斑马鱼幼鱼造成了体长变短、脊柱弯曲等形态变化;除丙烯菊酯外,其他3种农药均使斑马鱼幼鱼出现显著的运动活性降低趋势(P<0.05);在神经化学方面,与空白组和对照组相比,4种农药均使斑马鱼幼鱼体内的AchE活性显著下降(P<0.05);但4种农药对ROS水平变化各有差异:溴氰菊酯与高效氯氰菊酯对斑马鱼幼鱼的ROS水平影响无显著性差异,而丙烯菊酯和顺式氰戊菊酯在高中剂量下均可导致斑马鱼幼鱼ROS水平显著增加。结论 拟除虫菊酯农药对斑马鱼幼鱼产生了显著的神经毒性作用,首次发现形态变化和AchE活性的变化与大鼠相关结果体现出较好的一致性,有望替代大鼠用于更加简便快捷的食品安全风险评估;其余指标与大鼠呈现不同程度的差异,可能与两者生物学特性的差别有关。本研究为斑马鱼在食品安全评价中的应用提供参考。

混配农药中毒防治研究

首次在我国开展大规模的混配农药中毒流行病学调查,发现接触混配农药是当前发生农药中毒的重要危险因素,为针对性的预防提供了科学依据。毒理学研究证实多数农药混剂呈增毒效应或协同作用,且与其毒代动力学变化有密切关系,为今后开发高效、低毒的混配农药提供了毒理学依据。在国内外首次建立甲基对硫磷单克隆抗体酶联免疫测定法,并成功研制便携式血胆碱酯酶快速测定仪;这些检测接触、效应生物标志物的灵敏、特异、便捷的方法已试用于现场,并具有开发为产品的前景。同时还发现对氧磷酶基因在192位点的单核苷酸多态性,可能是甲基对硫磷免疫毒性作用的易感性生物标志物之一。在总结不同类别农药混配后所致中毒的临床表现特点和规律的基础上,修订现行的农药中毒诊断标准,增添了有机磷单剂及混剂中毒所致“中间期肌无力综合征”的新内容,将提高我国农药中毒的诊治水平。本研究主要成果达国内领先和国际先进水平。

东部近海海产品中有机氯和菊酯类农药的 分布特征与健康风险评估

为全面了解我国东部近海海产品中有机氯农药(OCPs)和菊酯类农药(PYRs)的残留特征及健康风险,本研究以我国东部近海附近海域的典型海产品为研究对象,使用气相色谱-三重四极杆串联质谱仪(GC-MS/MS)对其体内两类农药的含量进行测定和相关分析。结果显示:东部近海海产品中,ΣOCPs残留范围为2.2~1864.7 ng·g^(-1)(均值为72.5 ng·g^(-1),以干质量计),ΣPYRs浓度范围为5.2~761.7 ng·g^(-1)(均值为57.9 ng·g^(-1))。与软体动物类和甲壳类相比,ΣOCPs更容易蓄积在脂肪含量更高的鱼类中,而ΣPYRs在3类生物中的残留量差异不显著;空间分布上,两类农药在海洋生物体内残留量的空间差异性均不显著(除烟台海域外);来源分析表明,OCPs污染主要源于历史残留,而PYRs可能与近海范围内陆域的城市卫生防护活动密切相关。研究表明,不同海产品中两类农药的总风险指数远小于1,健康风险处于安全水平。

加压流体萃取-气相色谱-质谱法测定土壤和沉积物中32种有机磷类及8种拟除虫菊酯类农药残留

建立了加压流体萃取-气相色谱-质谱法测定土壤和沉积物中32种有机磷农药和8种拟除虫菊酯类农药的方法。选用正己烷/丙酮(体积比1∶1)混合溶液作为萃取溶剂,采用加压流体萃取仪对土壤和沉积物样品进行萃取,经石墨化炭黑固相萃取小柱净化后,内标法定量。实验结果表明,32种有机磷农药和8种拟除虫菊酯类农药在质量浓度10.0~100.0 mg·L^(-1)范围内线性关系良好,校准曲线中目标化合物相对响应因子的相对标准偏差均<20%,检出限为0.1~0.3 mg·kg^(-1),以空白样品为基体进行低、中、高三个浓度的加标回收试验,平均回收率分别为60.0%~100%、70.0%~90.0%、70.0%~104%,实验室内相对标准偏差(RSD)分别为:0.00%~13.0%、1.25%~15.3%、1.14%~19.1%。该方法具有操作简便、灵敏度高、精密度及准确性好等特点,可满足土壤和沉积物中32种有机磷农药和8种拟除虫菊酯类农药的分析要求。

QuEChERS-气相色谱-串联质谱测定水产品中的12种拟除虫菊酯类农药

建立了QuEChERS-气相色谱-串联质谱同时测定水产品中12种拟除虫菊酯类农药的检测方法。鱼、小龙虾样品经匀浆和QuEChERS前处理后即可进行气相色谱-串联质谱检测。12种拟除虫菊酯类农药在5~200μg/L浓度范围内线性良好,相关系数r 2≥0.9992,各组分的检出限(LOD)为3μg/kg,定量限(LOQ)为10μg/kg,满足国家标准(GB 31650-2021)限量值的分析要求。各组分在1LOQ、3LOQ、10LOQ的添加水平下,在鲫鱼、鳊鱼、草鱼和小龙虾中的回收率在81.5%~115.3%,相对标准偏差(RSD,n=3)均小于15%。本方法前处理简单高效,可用于水产品中12种拟除虫菊酯类农药的快速筛查。