烟草中有机氯农药残留标准测定方法的改进

为提高烟草中有机氯农药残留的检测种类和速度,对ISO 4389:2000(GB/T 13596-2004)法进行了改进.即用50%(体积分数)正己烷和50%(体积分数)丙酮混合溶剂代替正己烷作萃取剂,用加速溶剂萃取代替索氏萃取,对萃取温度进行了优化,并采用改进法和ISO 4389:2000法分别检测了国内外65个烟草样品中有机氯农药残留.结果表明:①该法检出10个样品中残留β-硫丹,而GB/T 13596-2004法未检出;②除β-硫丹外,两种方法检出烟草样品中的有机氯农药的种类几乎一样,且测定量之间的差异符合痕量农药测定的变异系数在20%以下的要求;③17个烟叶样品中未检出任何有机氯农药,占所选烟叶样品数的26.2%,其它样品都或多或少地残留有机氯农药;④o,p'-DDT的检出率最高,达到43.1%,所有样品中均未检出狄氏剂和异狄氏剂;⑤国内外卷烟样品中检出的残留的有机氯农药种类分别为47个和43个.其中,进口卷烟中均检出了有机氯农药,且主要为α-硫丹、β-硫丹和o,p'-DDT,而国产卷烟中主要在4个样品中检出了这些农药;⑥国产烟叶样品中残留的有机氯农药种类比进口样品稍多,且都主要是由某些样品中检出,其它样品中残留的有机氯农药的种类较少;⑦所有检测样品中有机氯农药的残留量均低于CORESTA推荐限量.该法萃取自动化程度高,萃取时间(25 min)短,可替代ISO 4389∶2000法进行烟草样品中有机氯农药残留的快速检测.     

固相萃取-气相色谱法测定玉米中有机氯和 拟除虫菊酯农药残留量

目的建立气相色谱-电子捕获检测器法(GC-ECD)测定玉米中16种有机氯和拟除虫菊酯农药残留量的方法。方法玉米样品经乙腈超声提取后,使用Florisil进行固相萃取净化,样品经氮吹浓缩后,使用气相色谱电子捕获检测器测定。结果 16种有机氯和拟除虫菊酯农药在0.01~0.5 mg/L浓度范围内呈现良好线性关系,R2大于0.99;在0.02、0.05、0.2 mg/kg三个添加浓度上回收率范围为71.0%~103%,相对标准偏差1.28%~8.74%,检出限在0.1~16μg/kg之间。结论该方法前处理操作快速简单,能够有效净化样品,满足玉米中有机氯和拟除虫菊酯农药的日常检测和监管工作,适用于大批次样品的定性定量分析。     

不同年生西洋参中20种有机氯农药的气相色谱分析

建立西洋参中α-六六六(α-BHC)、4,4'-滴滴涕(4,4'-DDT)等20种有机氯农药残留量的一种简便有效的气相色谱分析方法,对陕西留坝县西洋参GAP生产基地不同种植地块、不同生长年限西洋参中有机氯农药的种类和含量进行测定,并探讨不同生长年限西洋参中有机氯农药富集规律。样品有机氯农药残留用正己烷-乙酸乙酯(1:1)溶液提取,通过弗罗里硅土小柱净化,正己烷-乙酸乙酯(1:1)溶液洗脱后浓缩定容,采用DB-17毛细管柱分离,气相色谱-电子捕获检测器(gas chromatography -electron capture detector,GC-ECD)检测,以保留时间定性,外标法定量。结果表明：10个西洋参样品中除异狄氏剂未检出外,标准溶液中的其他19种有机氯农药均有检出。不同种植地块同一生长年限西洋参有机氯农药残留含量差异较大,西洋参中有机氯农药残留含量基本呈现4年生西洋参高于3年生西洋参和5年生西洋参的规律。实验建立的方法简便有效,适用于西洋参中有机氯农药残留量的测定。     

猪肉中有机氯农药多组分的顶空固相微萃取-气相色谱-质谱检测技术初探

目的探讨建立顶空固相微萃取快速测定有机氯农药残留方法。方法以稳定性同位素13C6-六氯苯和13C10-灭蚁灵为内标,以顶空固相微萃取作为猪肉样品的前处理手段,采用气相色谱-质谱的选择离子模式(SIM)测定猪肉样品中18种有机氯农药组分。通过对萃取头类型、萃取时间、萃取温度、解析温度和时间、盐溶液的浓度等影响萃取效率的因素的研究,获得了优化的试验参数。结果在给定条件下,方法线性范围在1~100ng/kg范围内,混和标准溶液的加标回收率在90%~120%之间,相对标准偏差在3%~15%之间。结论本方法适合于猪肉样品中的有机氯农药多残留的快速检测,为农药残留的筛选提供了有效的监测手段。     

一种同时测定保健食品中多种农药残留的方法

介绍一种同时测定保健食品中残留的有机氯、菊酯和有机磷类农药的方法。该法使用气相色谱法,双色谱柱双检测器同时分析,采用一致的柱温箱程序升温条件。各类有机磷农残回收率在88.47%~98.87%之间,RSD在1.05%~6.46%之间;各类有机氯农残回收率在88.84%~94.64%之间,RSD在0.66%~4.86%之间;各菊酯类农残回收率在88.09%~99.91%之间,RSD在1.73%~5.54%之间。此分析方法可用于保健品中多种农药残留量的同时测定。     

气相色谱法测定茶叶中13种有机氯农药残留

利用气相色谱(GC)技术建立了茶叶中13种有机氯农药残留同时测定的方法。茶叶样品中有机氯农药残留通过乙腈溶液提取,浓缩后SPE(TPT)净化,采用乙腈-甲苯(3+1)溶液淋洗,收集经过液旋转蒸发后用正己烷进行溶剂交换,气相色谱-电子捕获检测器(GC-ECD)同时测定茶叶中13种有机氯。分析本方法茶叶样品在0.1μg/m L和0.5μg/m L两个添加水平的回收率为76.1%-111.5%和82.2%-106.2%,相对标准偏差分别为1.21%-25.9%和1.42%-11.0%。本方法灵敏、快速、准确、可靠,用于茶叶样品中常见有机氯农药残留测定,获得较好结果。     

气相色谱法测定北沙参中有机氯农药的残留量

目的建立同时测定北沙参中9种有机氯农药残留量的气相色谱法(gas chromatography,GC)。方法以丙酮为提取剂,使用Elite-1701毛细管色谱柱,采用程序升温,ECD检测器检测,外标法定量测定北沙参中有机氯农药残留量。结果 Elite-1701柱对9种有机氯农药的分离度良好,在1.5~250μg/L范围内,浓度与峰面积呈现出良好的线性关系。平均加标回收率为79.47%~104.03%,相对标准偏差(relative standard deviations,RSDs)为2.61%~10.1%(n=6)。结论本研究的方法简便、快速、准确、稳定,可用于测定北沙参中9种有机氯农药残留量。     

磁性三维石墨烯复合材料的制备及其在有机氯农药残留检测中的应用

目的 建立磁性三维石墨烯复合材料-磁固相萃取-气相色谱法同时测定水样中8种有机氯农药残留。方法 通过氧化还原自组装制备四氧化三铁/三维石墨烯复合材料(Fe3O4/three-dimensional graphene nanocomposite, Fe3O4/3DG)作为磁固相萃取技术的萃取材料, 将其用于涡旋萃取样品中的有机氯农药残留, 再用丙酮将其解吸, 解吸剂经0.22 μm滤膜过滤后用气相色谱-电子捕获器分离检测, 外标法定量。结果 制备的磁性三维石墨烯复合材料兼具三维石墨烯高吸附性和Fe3O4强磁性。所建立的方法对8种有机氯农药残留的检出限范围为0.05~0.23 μg/L, 方法重现性为4.93%~9.42%, 线性范围在0.05~100 μg/L之间, 线性相关系数r2>0.9950。将本方法应用于环境水样中有机氯农药残留的分析检测, 加标回收率为75%~122%。结论 本方法操作简便、准确性好、灵敏度高, 适用于水样中8种有机氯农药残留的同时分析。     

气相质谱联用法测定西洋参有机氯类农药残留

有机氯农药是一类人工合成的杀虫广谱、残效期长的化学杀虫剂。《中国药典》对我国中药材有机氯农药限量做了规定,允许限量范围在0.05mg/kg-3mg/kg。本文通过对前处理方法进行优化,用0.1%乙酸乙腈溶液做提取剂,采用超声波提取法,建立了测定西洋参中10种有机氯类农药残留量的气相色谱-质谱联用法。结果显示:应用此方法可使10种有机氯类农药在35分钟之内完全分离,方法线性良好,相关系数(R2)均可达到0.999以上,方法检出限(LOD)和定量限(LOQ)分别为0.1ug/kg、0.3ug/kg,均低于《中国药典》中10种有机氯农药残留的最低限量~([1])。所以得出结论:该方法简单、运行时间短、灵敏度高,适用于西洋参样品中有机氯农药残留量的检测~([2])。     

鸡蛋、鸡肉及奶粉中22种有机氯农药残留的测定

建立了在鸡蛋、鸡肉和奶粉中同时测定22种有机氯农药残留的方法。样品经乙腈提取、Captiva EMR-Lipid固相萃取柱净化、正己烷复溶后,用气相色谱仪检测,外标法定量。在0.005~0.2 mg/L范围内,22种有机氯农药的质量浓度与其对应的峰面积之间线性关系良好,R²均大于0.995。在0.01、0.02、0.1 mg/kg 3个添加水平下,重复测定6次,22种有机氯农药的回收率均在60%~110%,RSD均小于10%,符合GB 27404—2008的实验室内变异系数要求。该方法能够有效去除鸡蛋、鸡肉和奶粉中的动物脂肪及亲脂性干扰物,方法灵敏度、准确度和精密度均符合农药残留检测的要求,为有效监测鸡蛋、鸡肉和奶粉中有机氯农药残留量提供了一种高效、可靠的分析手段。     

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.     

Analysing organochlorine pesticides in strawberry jams using GC-ECD, GC-MS/MS and QuEChERS sample preparation

This paper describes a comparison of adaptations of the QuEChERS (quick, easy, cheap, effective, rugged and safe) approach for the determination of 14 organochlorine pesticide (OCP) residues in strawberry jam by concurrent use of gas chromatography (GC) coupled to electron capture detector (ECD) and GC tandem mass spectrometry (GC-MS/MS). Three versions were tested based on the original QuEChERS method. The results were good (overall average of 89% recoveries with 15% RSD) using the ultrasonic bath at five spiked levels. Performance characteristics, such as accuracy, precision, linear range, limits of detection (LOD) and quantification (LOQ), were determined for each pesticide. LOD ranged from 0.8 to 8.9 μg kg(-1); LOQ was in the range of 2.5-29.8 μg kg(-1); and calibration curves were linear (r(2)>0.9970) in the whole range of the explored concentrations (5-100 μg kg(-1)). The LODs of these pesticides were much lower than the maximum residue levels (MRLs) allowed in Europe for strawberries. The method was successfully applied to the quantification of OCP in commercially available jams. The OCPs were detected lower than the LOD.     

Analysing organochlorine pesticides in strawberry jams using GC-ECD,GC-MS/MS and QuEChERS sample preparation

This paper describes a comparison of adaptations of the QuEChERS (quick, easy, cheap, effective, rugged and safe) approach for the determination of 14 organochlorine pesticide (OCP) residues in strawberry jam by concurrent use of gas chromatography (GC) coupled to electron capture detector (ECD) and GC tandem mass spectrometry (GC-MS/MS). Three versions were tested based on the original QuEChERS method. The results were good (overall average of 89% recoveries with 15% RSD) using the ultrasonic bath at five spiked levels. Performance characteristics, such as accuracy, precision, linear range, limits of detection (LOD) and quantification (LOQ), were determined for each pesticide. LOD ranged from 0.8 to 8.9?µg?kg^?1; LOQ was in the range of 2.5–29.8?µg?kg^?1; and calibration curves were linear (r ^2?>?0.9970) in the whole range of the explored concentrations (5–100?µg?kg^?1). The LODs of these pesticides were much lower than the maximum residue levels (MRLs) allowed in Europe for strawberries. The method was successfully applied to the quantification of OCP in commercially available jams. The OCPs were detected lower than the LOD.     

Multiresidue analysis of 30 organochlorine pesticides in milk and milk powder by gel permeation chromatography-solid phase extraction-gas chromatography-tandem mass spectrometry

A method for simultaneous determination of the 30 organochlorine pesticides (OCP) in milk and milk powder samples has been developed. Prior to the gas chromatography-tandem mass spectrometric analysis, the residual OCP in samples were extracted with n-hexane and acetone mixture (1/1, vol/vol) and cleaned up by gel permeation chromatography and solid phase extraction. Selected reaction monitoring mode was used for gas chromatography-tandem mass spectrometric data acquisition to identify and quantify the OCP. To avoid the matrix effects, matrix-matched calibration solutions ranging from 2 to 50 ng/mL were used to record the calibration curve. Limits of quantification of all OCP were 0.8 μg/kg. With the exception of endrin, limits of quantification are signi?cantly lower than maximum residue limits set by the European Union and China. The average recoveries were in the range of 70.1 to 114.7% at 3 spiked concentration levels (0.8, 2.0, and 10.0 μg/kg) with residual standard deviation lower than 12.9%. The developed method was successfully applied to analyze the OCP in commercial milk products.     

Persistent organic pollutants in farmed European sea bass (Dicentrarchus labrax,Linnaeus, 1758) from Sicily (Italy)

Farmed European sea bass (Dicentrarchus labrax, Linnaeus, 1758) were collected during 2016 from one Sicilian fish farm that uses two different rearing systems – sea cage and concrete tank – for determination of polychlorinated biphenyls (PCB), organochlorine pesticides (OCP) and polycyclic aromatic hydrocarbons (PAH) residues by HRGC-MS/MS. Moreover, commercial feed was analysed. This study aimed to determine whether the different rearing systems affect the concentration of these compounds, and to assess the safety of cultured fish. PCBs represent the pollutants with the highest concentration; in particular, PCB138 and 153 have the highest concentration in almost all samples. Among OCPs, only 4,4′-DDE, 4,4′-DDD and 4,4′-DDT residues have been detected. Concerning PAHs, only fluorene and phenanthrene were detected, in both rearing systems. Although some residues of organic pollutants were found in the analysed samples, they were always below the MRLs, so the results suggest that farmed sea bass are safe for human consumption.     

Analysis of triazine herbicides residues in butter and pasteurized milk

A method has been developed for the determination of atrazine, cyanazine, prometryn, simazine, and terbutryn residues in butter. The residues were extracted from the matrix with a mixture of petroleum ether/methanol (3 + 1), and from the separated water-methanol phase extraction was carried out with chloroform. The extract was cleaned up on an alumina column. Capillary glass liquid chromatography using a 15 m x 0.32 mm glass capillary column coated with OV-1 and an alcali flame ionization detector were employed for the analysis of the residues. The analyses were evaluated by the internal standard method, using metribuzin as the internal standard. The recovery of the method was 68.7%-79.8% for the individual herbicides under study at the fortification level of 0.1 mg.kg-1 and 79.2%-91.9% at the fortification level of 0.02 mg.kg-1. The determination limit of the method was 0.005 mg.kg-1. When centrifuging full milk, residues of triazines were partitioned between the water and fat phases, whereby 17%-82% of the residues were transferred to the milk fat. Samples of commercial butter were analysed and found to contain 0.005-0.023 mg.kg-1 atrazine.     

A survey of extractable persistent organochlorine pollutants in Chinese commercial yogurt

Eighteen Chinese commercial brands of yogurt were collected from supermarkets from December 2002 to April 2003, for characterization of organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB). Besides monitoring OCP and PCB by gas chromatography, the levels of extractable persistent organochlorine (EPOCl; i.e., sulfuric acid-resistant EPOCl) were also determined by instrumental neutron activation analysis. The results indicated that the contamination pattern of the selected OCP and PCB were in the order of dichlorodiphenyltrichloroethanes (DDT) approximately hexachlorocyclohexanes (HCH) > aldrin > or = chlordanes > or = heptachlor epoxide and 4-6 chlorinated biphenyls (CB) > 7-10 CB, respectively. Furthermore, beta-HCH, and 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene were the predominant isomers of HCH and DDT residues in yogurt, and PCB with 4,4'- and 2,3,5- substitution patterns were the predominant congeners of PCB residues. Also, the results indicated that the mean level of total chlorine in the identified organochlorine species was below 4% of EPOCl in yogurt, which implied that more than 96% of EPOCl measured in yogurt samples could not be accounted for by selected OCP and PCB.     

DETERMINATION OF PIRIMIPHOS-METHYL IN PASTA BY GAS CHROMATOGRAPHY/CHEMICAL IONIZATION MASS SPECTROMETRY

A method for the determination of pirimiphos-methyl residues in pasta has been developed. The pesticide was extracted from pasta using the Luke procedure modified for low moisture, nonfatty food products. The extracts were analyzed by capillary column gas chromatography using an ion trap mass spectrometer in the chemical ionization mode as the detector. Quantification was performed using fluorene as the internal standard. The limit of detection was 0.005 ppm. Recoveries from spaghetti were 83.0% at the 0.100 ppm level and 93.3% at the 0.010 ppm level. Of 48 spaghetti samples analyzed, 38 contained detectable residues between trace (>0.005 ppm) and 0.180 ppm. Electron ionization (EI) was used to confirm residues as low as 0.016 ppm in more concentrated extracts.     

平行定量浓缩仪- 超高效液相色谱- 串联质谱联用快速检测鳗鱼中8 种喹诺酮类药物残留量

建立鳗鱼肉中8种奎诺酮残留量的平行定量浓缩仪-超高效液相色谱-串联质谱检测方法。以氘代试剂为内标,样品经酸化乙腈萃取后,平行定量浓缩仪浓缩,用正己烷脱脂,采用超高效液相色谱-串联质谱选择反应监测正离子模式测定,可同时对鱼肉中奎诺酮进行定性和定量。奎诺酮检出限可达0.5μg/kg,定量低限可达1.0μg/kg。在2.5～200ng/mL范围内峰强度与质量浓度的线性关系良好(r＞0.99)。方法的平均回收率在81.4%～111.1%之间。方法简单、快速、稳定、准确、灵敏度高,适合于实验室大批量检测水产品样品。     

DMSO辅助浓缩气相色谱-质谱联用仪测定水产品中6种丁香酚类化合物

建立了水产品中6种丁香酚类化合物的二甲亚砜(DMSO)辅助浓缩-气相色谱-质谱联用仪(GC-MS)测定方法。试样加入无水硫酸钠后,以乙腈为提取溶剂,乙腈饱和的正己烷脱脂,乙腈层加入二甲亚砜(DMSO)辅助氮吹浓缩至近干;采用DB-1701色谱柱进行分离,并用质谱进行检测。6种化合物在20~1000 μg/L内呈良好的线性关系(相关系数大于0.999);在四种基质中的加标水平分别为0.02、0.04、0.10 mg/kg时,6种化合物平均加标回收率为64.8%~110.9%,相对标准偏差均不大于15%(n=6);方法定量限为0.02 mg/kg。该方法灵敏、准确度高、快速、线性范围宽、选择性好、前处理简单,并解决了目前文献方法中仅直接氮吹浓缩对回收率影响很大的关键问题,适用于水产品中丁香酚类化合物的准确定性定量检测,可用于水产品中该类麻醉剂的摸底监测。