农产食品中菊酯类农药残留量的气相色谱快速分析方法

1　前言菊酯类农药是一种广泛应用于农业和家庭防虫的化学品,由于具有杀虫谱广、施用量小、杀虫速效、持效期长而低残毒等特点,其使用愈来愈普遍[1]。本文介绍了用一根色谱柱同时测定食品中的菊酯类农残的快速分析方法,样品中的菊酯类农残经丙酮-石油醚萃取,用无水硫酸钠-中性氧化铝净化,加入活性炭粉脱色,用气相色谱-电子捕获检测器测定。其回收率范围为90.2%-109.1%,检测限范围为0.0005mg/kg-0.002mg/kg,能满足残留量分析的要求。2　实验部分[2-8]2.1　主要仪器和试剂2.1.1　仪器岛津GC-7AG气相色谱仪附电子捕获检测器(ECD)、高速组织…     

气相色谱-电子捕获检测器快速测定水产品中多种农药及兽药残留北大核心CSCD

称取2.000g样品,加入含0.2%(φ)甲酸的乙腈(85+15)溶液10mL,涡旋混合30s,振荡提取30min,以10 000r·min-1转速离心5min,取上清液。用2mL的含0.2%(φ)甲酸的乙腈(85+15)溶液活化Oasis PRiME HLB小柱后,将上述上清液全部通过Oasis PRiME HLB小柱并收集滤液,于50℃水浴下氮吹至干,加入100μL衍生化试剂[N,O-双(三甲基硅烷基)三氟乙酰胺-三甲基氯硅烷(质量比为99∶1)],涡旋10s,于65℃恒温反应30min后,于50℃水浴下氮吹至干,用正己烷定容至1.0mL,以DB-5/DB-35色谱柱(30m×0.25mm,0.25μm)分离11种拟除虫菊酯类农药和3种氯霉素类兽药,采用电子捕获检测器。11种农药的线性范围为0.10~0.80mg·L-1,3种兽药的线性范围为5.0~40mg·L-1,检出限(3S/N)在0.000 1~0.008 0μg·g-1之间。加标回收率为85.6%~119%,测定值的相对标准偏差(n=6)不大于9.0%。     

气相色谱/双柱双检测器测定塑料制品中10种有机锡

将不同材质塑料样品用四氢呋喃溶解,再用甲醇沉淀杂质大分子后高速离心过滤,各有机锡在乙酸-乙酸钠缓冲溶液中与四乙基硼酸钠反应生成有机锡的乙基化衍生物,经正己烷萃取后进行气相色谱定性、定量分析,并对衍生化条件(如衍生时间、酸度、衍生试剂)进行优化。用双柱-质谱和火焰光度双检测器/气相色谱法测定了PVC,PC,PS,AS及ABS不同塑料样品中的二甲基锡、三甲基锡、二乙基锡、一丁基锡、二丁基锡、四丁基锡、二辛基锡、三环己基锡、二苯基锡和三苯基锡共10种有机锡化合物。采用外标法定量,在0.01~10 mg·L-1浓度范围内,各有机锡化合物均呈良好线性,其相关系数(r)均大于0.999。测得PVC,PS,ABS不同塑料样品中10种有机锡的回收率为75.1%~110.1%,相对标准偏差(n=6)小于10%,检出限为0.005~0.037 mg/kg。该方法重复性好,操作简单,灵敏度高,能广泛应用于各种塑料制品中多种有机锡的检测。     

海水中14种有机磷农药的气相色谱测定方法

建立了毛细管气相色谱-火焰光度检测器测定海水中14种有机磷农药的方法。用CH2Cl2液液萃取pH 6~8范围内的样品,然后采用毛细管柱及火焰光度检测器进行测定。在0.005~0.3μg/mL范围,相关系数为0.9904%~0.9996%。方法检出限低和精密度高,相对标准偏差为1.71%~5.89%。该方法具有灵敏、快速、简便等特点。     

双柱双检测器气相色谱法测定水样中多氯联苯Aroclor系列

采用液液萃取技术提取水样中多氯联苯系列有机物,经浓硫酸和硅胶柱净化浓缩后,利用气相色谱法分离,双电子捕获检测器(ECD)检测,根据双柱的保留值进行多氯联苯Aroclor系列的定性和定量分析。多氯联苯的基体加标回收率为73.5%～108.1%,方法检出限为0.051～0.083μg/L。     

气相色谱新型火焰光度检测器及其性能研究

气相色谱新型火焰光度检测器及其性能研究江桂斌，徐福正（中国科学院生态环境研究中心，北京１０００８５）现有的气相色谱火焰光度检测器（ＦＰＤ）是Ｂｒｏｄｙ和Ｃｈａｎｅｙ在１９６６年首先设计使用的￣［１］，这种检测器所用的氢火焰周围是空气，属于一种气相发射...     

气相色谱-电子捕获检测器同时测定茶叶中有机氯及拟除虫菊酯类农药残留

在超声波辅助下,以正己烷-二氯甲烷（1：1,V／V）混合溶剂提取样品,提取液用弗罗里硅土和中性氧化铝混合柱净化,用气相色谱-电子捕获检测器（GC-ECD）同时测定茶叶中18种有机氯和9种拟除虫菊酯类农药残留。有机氯农药在0.001-0.2μg／mL,拟除虫菊酯类农药在0.005-1.0μg／mL范围内线性良好。有机氯农药在0.04、0.01μg／mL两个添加水平的回收率分别为89.5％-113.2％和80.0％-112.7％,相对标准偏差分别为3.82％-9.64％和5.32％-13.8％。拟除虫菊酯在0.2、O.05μg／mL两个添加水平的回收率分别为97.5％-129.6％和87.3％-110.2％,相对标准偏差分别为3.78％-10.72％和3.02％-13.84％。本方法快速、灵敏、准确、可靠,用于江西茶叶样品中有机农药残留测定,获得较好结果。     

气相色谱-质谱法测定多种农药残留

文中比较了气相色谱-负化学离子源-质谱法(GC-NCI-MS)与气相色谱-电子轰击离子源-质谱法(GC-EI-MS)分析多种农药残留量方法中的选择离子、质谱图、线性范围、检出限等指标,试验结果表明:GC-NCI-MS质谱图的碎片离子少,线性范围宽,11种农药除二嗪农及o,p'-DDT外,负化学离子源(NCI)的检出限都低于电子轰击离子源(EI)至少一个数量级;同一个样品,GC-NCH-MS的质谱图杂峰更少.若分子中含有易获得电子的基团,NCI源比EI源有更高的灵敏度和选择性.     

气相色谱-双柱双电子捕获检测器测定土壤及沉积物中23种有机氯农药

建立了微波萃取,弗罗里硅土固相萃取柱及铜粉除硫净化,双柱双电子捕获检测器(ECD)-气相色谱法(GC)测定5种不同质地土壤及5处不同来源沉积物中的23种有机氯农药(OCPs)。采用内标法定量,在0.005～0.5 mg/L的质量浓度范围内,替代物和各种农药标准品的线性相关系数(r2)均大于0.997。5种土壤及5处沉积物中23种OCPs的平均加标回收率分别为50%～119%和52%～120%,相对标准偏差分别为0.9%～16.1%(n=6)和0.3%～28.4%(n=6),检出限为0.00005～0.0005 mg/kg。结果表明,该方法重现性好、灵敏度高、线性关系好,可以满足简便、快速、准确测定农药残留的要求,可大范围推广使用。     

双气相色谱-双脉冲火焰光度法高通量检测动物性食品中有机磷农药残留及其代谢产物

建立了动物性食品中包括代谢产物在内的54种有机磷农药残留及其代谢产物的双气相色谱-双脉冲火焰光度检测器(GC-PFPD)检测方法。动物组织样品经丙酮提取后以二氯甲烷进行液-液萃取,经凝胶渗透色谱净化后采用配有双脉冲火焰光度检测器的气相色谱仪测定。采用外标法定量,有机磷农药的响应与其浓度在线性范围内均呈良好的线性关系,相关系数在0.9905～0.9999之间。分别在空白鸡肉、羊肉、牛肉和猪肉样品中添加低、中和高3个加标水平的标准品进行了回收试验,回收率在50.5%～128.1%之间,相对标准偏差(n=6)在1.1%～25.5%之间,证明该方法的精密度和准确度良好。各有机磷农药的检出限在0.001～0.170 mg/kg之间,定量限在0.002～0.455 mg/kg之间。对从市场采集的动物组织样品进行了测定,检出敌敌畏、乙拌磷亚砜等有机磷农药残留。本方法灵敏度高、特异性强,且能同时检测有机磷农药多残留及其代谢产物,能够更加真实地反映动物性食品中有机磷农药的残留水平。     

气相色谱法测定苹果中的多种农药残留量

采用丙酮和正己烷提取,C18固相萃取小柱净化,气相色谱法用电子捕获检测器（GC-ECD）测定,建立了苹果中有机氯、拟除虫菊酯和有机磷3类15种农药的同时检测方法.该方法的回收率为78.3%～104.2%、相对标准偏差≤6.2%.     

气相色谱-电子捕获检测法测定海水中十氯酮残留

通过考察提取溶剂、毛细管柱、净化条件及共溶出干扰物等因素对十氯酮测定的影响,建立了二氯甲烷液-液富集萃取、硫酸净化分离、气相色谱法(GC)-电子捕获检测器(ECD)测定海水介质中有机氯农药类持久性有机污染物十氯酮残留分析方法。1 L海水经50 mL二氯甲烷萃取富集,浓缩后采用硫酸净化,以1%(体积分数)甲醇/正己烷混合溶液转移定容后,采用DB-5非极性毛细管柱进行GC分离,电子捕获检测器可测定其中十氯酮的含量;该方法采用外标法定量,在5～100 μg/L范围内呈线性,线性相关系数为0.9989。低、中、高3个浓度水平的平均加标回收率为81%～108%,相对标准偏差为1.2%～5.1%(n=6)。方法的检出限为0.6 ng/L。结果表明,该方法灵敏度高,线性关系好,可以满足简便、快速、准确测定海水中十氯酮的要求。     

Determination of chloramphenicol residue in chicken tissues by immunoaffinity chromatography cleanup and gas chromatography with a microcell electron capture detector

A rapid and sensitive gas chromatography (GC) method was developed to detect chloramphenicol in chicken tissues. The extracted samples were cleaned up using the immunoaffinity column prepared by coupling antichloramphenicol monoclonal antibody with cyanogen bromide-activated Sepharose 4B. The dynamic column capacity of chloramphenicol was 3265 ng/mL gel. The eluate was evaporated to dryness, and residues were derivatized and determined by GC with a microcell electron capture detector. Average recoveries were 86.6 to 96.9% for chicken muscle and 74.3 to 96.1% for chicken liver. The limit of quantitation of the method was 0.05 ng/g for chicken muscle and 0.1 ng/g for chicken liver.     

Determination of chloramphenicol residue in fish and shrimp tissues by gas chromatography with a microcell electron capture detector

A gas chromatography method with microcell electron capture detection was developed for the determination of chloramphenicol residue in fish and shrimp muscle tissues. The tissue samples were extracted with ethyl acetate, defatted with hexane, and derivatized with Sylon BFT [N,O-bis (trimethylsilyl) trifluoroacetamide-trimethylchlorosilane (99 + 1)]. The limit of detection was 0.04 ng/g and the limit of quantitation 0.1 ng/g. Average recoveries were 70.8-90.8% for fish and 69.9-86.3% for shrimp, respectively. The method was validated for the determination of practical samples.     

气相色谱-微池电子捕获器检测尿液中的三唑仑

建立了气相色谱-微池电子捕获检测器(GC-μECD)检测尿液中三唑仑的方法。筛选了pH值、提取溶剂、涡旋时间,优化了液-液萃 取条件。在0.2～50 ng/mL范围内,线性关系良好,相关系数为0.9995;方法的检出限为0.1 ng/mL,日内和日间测定的相对标准偏差分 别为4.17%和5.31%,平均回收率为93.9%。该方法操作简便、灵敏度高、线性范围广、回收率高,完全能够满足日常检测工作的需要。     

Determination of pyrethroid pesticide residues in processed fruits and vegetables by gas chromatography with electron capture and mass spectrometric detection

A gas chromatographic method was developed for the simultaneous determination of 12 pyrethroids (tefluthrin, bifenthrin, fenpropathrin, cyhalothrin, permethrin, cyfluthrin, cypermethrin, alpha-cypermethrin, flucythrinate, fenvalerate, fluvalinate, and deltamethrin) in tomato puree, peach nectar, orange juice, and canned peas. A miniaturized extraction-partition procedure requiring small amounts of nonchlorinated solvents is used. Samples are extracted with acetone, partitioned with ethyl acetate-cyclohexane (50 + 50, v/v), and cleaned up on a Florisil cartridge. The final extract is analyzed by gas chromatography with both electron capture and mass spectrometric detection modes. Studies at fortification levels of 0.010-0.100 mg/kg gave mean recoveries ranging from 70.2 to 96.0% and coefficients of variation between 4.0 and 13.9% for all compounds. Quantitation limits were < 0.010 mg/kg for electron capture detection.     

Determination of malathion, coumaphos, and fluvalinate residues in honey by gas chromatography with nitrogen-phosphorus or electron capture detectors

A rapid, reliable, and inexpensive extraction method was developed to determine acaricide residues in honey by gas chromatography (GC) with nitrogen-phosphorus (NP) or electron capture (EC) detectors. Because of the high selectivity of the NP detector, no interfering peaks were present and no cleanup was necessary. A simple cleanup step is proposed for the GC-ECD analysis. Recoveries from spiked honey samples ranged from 79 to 94.4%, with coefficients of variation of 0.3-18.5%. The quantitation limit obtained was 0.015 mg/kg for malathion, 0.020 mg/kg for coumaphos, and 0.005 mg/kg for fluvalinate. The method was used to determine the disappearance of malathion and coumaphos residues from honey samples collected from beehives treated with these acaricides. The disappearance of both acaricides was rapid and followed a first-order model for the duration of the experiment.     

Rapid determination of acrylamide contaminant in conventional fried foods by gas chromatography with electron capture detector

Gas chromatography coupled with electron capture detector (GC-ECD) was successfully developed and applied for the rapid determination of acrylamide in conventional fried foods, such as potato crisps, potato chips, and fried chicken wings. The method included defatting with n-hexane, extraction with aqueous solution of sodium chloride (NaCl), derivatization with potassium bromate (KBrO3) and potassium bromide (KBr), and liquid-liquid extraction with ethyl acetate. The final acrylamide extract was analyzed by GC-ECD for quantification and by GC-MS for confirmation. The chromatographic analysis was performed on the HP-INNOWax capillary column, and good retention and peak response of acrylamide were achieved under the optimal conditions (numbers of theoretical plates N = 83,815). The limit of detection (LOD) was estimated to be 0.1 microg kg(-1) on the basis of ECD technique. Recoveries of acrylamide from conventional samples spiked at levels of 150, 500 and 1000 microg kg(-1) (n = 4 for each level) ranged between 87 and 97% with relative standard deviations (RSD) of less than 4%. Furthermore, the GC-ECD method showed that no clean-up steps of acrylamide derivative would be performed prior to injection and was slightly more sensitive than the MS/MS-based methods. Validation and quantification results demonstrated that this method should be regarded as a new, low-cost, and robust alternative for conventional investigation of acrylamide.     

Determination of methylmercury in biological samples by capillary gas chromatography with electron capture detection

A precise and accurate method has been developed for the determination of methylmercury in biological material using capillary gas chromatography with electron-capture detection. Homogenized fish or mussel samples were digested with acid, spiked with ethylmercury chloride as an internal standard and extracted with toluene. After treatment of the solvent extract with sodium thiosulphate and cupric bromide the alkylmercurials were extracted into benzene as their bromide derivatives and analyzed using an OV-275 coated glass capillary column. The detection limit of the method for methylmercury was 5 g/kg tissue.     

Determination of nitroaromatic, nitramine, and nitrate ester explosives in soil by gas chromatography and an electron capture detector

Hazardous waste site characterization, forensic investigations, and land mine detection are scenarios where soils may be collected and analyzed for traces of nitroaromatic, nitramine, and nitrate ester explosives. These thermally labile analytes are traditionally determined by high-performance liquid chromatography (HPLC); however, commercially available deactivated injection port liners and wide-bore capillary columns have made routine analysis by gas chromatography (GC) possible. The electron-withdrawing nitro group common to each of these explosives makes the electron capture detector (ECD) suitable for determination of low concentrations of explosives in soil, water, and air. GC-ECD and HPLC-UV concentration estimates of explosives residues in field-contaminated soils from hazardous waste sites were compared, and correlation (r>0.97) was excellent between the two methods of analysis for each of the compounds most frequently detected: 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4-dinitrotoluene (2,4-DNT), 1,3-dinitrobenzene (1,3-DNB), 1,3,5-trinitrobenzene (TNB), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The analytes were extracted from soils with acetonitrile by 18 h of sonication in a cooled ultrasonic bath. Two soil-to-solvent ratios were evaluated: 2.00 g:10.00 ml and 25.0 g:50.0 ml. GC-ECD method detection limits were similar for the two soil-to-solvent ratios and were about 1 mug kg(-1) for the di- and trinitroaromatics, about 10 mug kg(-1) for the mono-nitroaromatics, 3 mug kg(-1) for RDX, 25 mug kg(-1) for HMX, and between 10 and 40 mug kg(-1) for the nitrate esters (nitroglycerine [NG] and pentaerythritol tetranitrate [PETN]). Spike recovery studies revealed artifacts introduced by the spiking procedure. Recoveries were low in some soils if the amount of soil spiked was large (25.0 g) compared to the volume of spike solution added (1.00 ml). Recoveries were close to 100% when 2.00-g soil samples were spiked with 1.00 ml of solution. Analytes most frequently found in soils collected near buried land mines were the microbial transformation products of TNT (2-amino-4,6-dinitrotoluene [2-Am-DNT] and 4-amino-2,6-dinitrotoluene [4-Am-DNT]), manufacturing impurities of TNT (2,4-DNT, 2,6-DNT, and 1,3-DNB), and TNT. The microbial reduction products of the isomers of DNT and of 1,3-DNB were also detected, but the ECD response to these compounds is poor.