固相萃取-气相色谱法测定茶叶中残留的92种农药

建立了茶叶中92种农药多残留的气相色谱分析方法。茶叶样品用乙腈一次性提取后,有机磷类农药经Envi-Carb固相小柱净化,用10 mL乙腈-甲苯(体积比为3∶1)洗脱剂淋洗,气相色谱-火焰光度检测器(GC-FPD)检测;有机氯类和拟除虫菊酯类农药经串联Envi-Carb和NH2固相小柱净化,用5 mL乙腈-甲苯(体积比为3∶1)洗脱剂淋洗,GC-电子捕获检测器(ECD)检测。采用外标法定量。添加回收试验的结果表明:92种农药的平均回收率为80.3%～117.1%,相对标准偏差为1.5%～9.8%。方法的检出限为0.0025～0.10 mg/kg。该方法的灵敏度、准确度和精密度均符合农药残留测定的技术要求。     

Determination of some organophosphorus and azole group pesticides in water samples by dispersive liquid-liquid microextraction coupled with GC/MS

A dispersive liquid-liquid microextraction (DLLME) procedure coupled with GC/MS detection is described for preconcentration and determination of some organophosphorus and azole group pesticides from water samples. Experimental conditions affecting the DLLME procedure were optimized by means of an experimental design. A mixture of 60 microL chlorobenzene (extraction solvent) and 750 microL acetonitrile (disperser solvent), 3.5 min extraction time, and 7.5 mL aqueous sample volume were chosen for the best recovery by DLLME. The linear range was 1.6-32 microg/L. The LOD ranged from 48.8 to 68.7 ng/L. The RSD values for organophosphorus and azole group pesticides at spiking levels of 3, 6, and 9 microg/L in water samples were in the range of 1.1-12.8%. The applicability and accuracy of the developed method were determined by analysis of spiked water samples, and the recoveries of the analyzed pesticides from artesian, stream, and tap waters at spiking levels of 3, 6, and 9 microg/L were 89.3-105.6, 89.5-103.0, and 92.0-111.3%, respectively.     

A high performance liquid chromatographic method for the screening of 17 diuretics in human urine

A simple and adequate HPLC method was developed for screening of human urine for the following 17 diuretic drugs: acetazolamide, bendrofluazide, bumetanide, canrenoic acid, chlorothiazide, chlorthalidone, clopamide, epitizide, etacrynic acid, furosemide, hydrochlorothiazide, indapamide, mefruside, piretanide, spironolactone, torasemide, and triamterene. The assay involves extraction from two 2 mL urine samples with ethyl acetate at pH = 5, washing with a phosphate buffer at pH = 6 and analysis by HPLC using a reversed phase C18 column and ultraviolet detection with a diode array detector for all drugs (except triamterene) using two eluents consisting of water, triethylamine, phosphoric acid and acetonitrile at different ratios and different pH values. Triamterene is determined by direct injection of diluted urine onto the column and is measured by fluorescence detection. The recoveries of the diuretic drugs were determined at two different concentrations and ranged from 43–110% (median: 87%) which is sufficient to detect abuse of these drugs. The repeatability of the assay ranged from 1–12% (median: 5.5%).     

固相萃取气相色谱-质谱法测定蔬菜中含氮杂环农药残留

建立了固相萃取（SPE）气相色谱-质谱（GC-MS）同时测定蔬菜中敌菌灵、噻菌灵、氟虫腈和噻嗪酮4种含氮杂环农药残留量的分析方法.蔬菜样品用乙腈匀浆提取后经弗罗里硅（Florisil）固相萃取柱净化.采用GC-MS检测,在选择离子检测（SIM）模式下以特征离子定量,用全扫描（SCAN）方法确证.方法具有良好的线性关系（R≥0.9953）和重现性（峰面积RSD≤9.1%）,最低检出限（S/N=3）在3.6~1.8×10-4μg/mL之间,4种农药添加回收率在76.1%~116.4%之间,RSD≤9.8%,用于实际样品菜心的检测,结果满意.方法操作简单,灵敏度高,可作为测定各种蔬菜基质中含氮杂环农药残留量的确证方法.     

Multiresidue determination of pesticides in juice by solid-phase extraction and gas chromatography-mass spectrometry

A multiresidue method based on solid-phase extraction was developed for the simultaneous determination of 50 pesticides in commercial juices. The extraction procedure was carried out in C₁₈ columns preconditioned with acetonitrile and water. The subsequent elution of pesticides was performed with a mixture of hexane-ethyl acetate (1:1, v/v) prior to the determination by gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC-MS-SIM), using one target and two qualifier ions. Standards were prepared spiking blank juice samples to counteract the observed matrix effect. Average recoveries for all the pesticides studied were higher than 91% with relative standard deviations lower than 9% in the concentration range of 0.02-0.1 μg/mL and the detection limits achieved ranged from 0.1 to 4.6 μg/L. The proposed method was applied to the analysis of these compounds in commercial juices and diazinon, ethion and procymidone were the pesticides encountered, although the levels found were very low.     

非衍生化高效液相色谱-串联质谱法快速检测生物体液中草甘膦、草铵膦及代谢物

建立了一种非衍生化高效液相色谱-串联质谱快速检测生物体液中草甘膦、草铵膦及其代谢物等8种极性农药的方法.8 种极性农药经Metrosep A Supp 5 阴离子色谱柱(150 mm x4.0 mm,5 μm)分离,以纯水-200 mmol/L碳酸氢铵溶液(含0.1％氨水)为流动相进行梯度洗脱,负离子多反应监测(MRM...     

A high performance liquid chromatographic method for the screening of 17 diuretics in human urine

A simple and adequate HPLC method was developed for screening of human urine for the following 17 diuretic drugs: acetazolamide, bendrofluazide, bumetanide, canrenoic acid, chlorothiazide, chlorthalidone, clopamide, epitizide, etacrynic acid, furosemide, hydrochlorothiazide, indapamide, mefruside, piretanide, spironolactone, torasemide, and triamterene. The assay involves extraction from two 2 mL urine samples with ethyl acetate at pH = 5, washing with a phosphate buffer at pH = 6 and analysis by HPLC using a reversed phase C18 column and ultraviolet detection with a diode array detector for all drugs (except triamterene) using two eluents consisting of water, triethylamine, phosphoric acid and acetonitrile at different ratios and different pH values. Triamterene is determined by direct injection of diluted urine onto the column and is measured by fluorescence detection. The recoveries of the diuretic drugs were determined at two different concentrations and ranged from 43–110% (median: 87%) which is sufficient to detect abuse of these drugs. The repeatability of the assay ranged from 1–12% (median: 5.5%). Received: 13 July 1998 / Revised: 23 October 1998 / Accepted: 29 October 1998     

Simultaneous determination of three organophosphorus pesticides in different food commodities by gas chromatography with mass spectrometry

A sensitive and selective gas chromatography with mass spectrometry method was developed for the simultaneous determination of three organophosphorus pesticides, namely, chlorpyrifos, malathion, and diazinon in three different food commodities (milk, apples, and drinking water) employing solid‐phase extraction for sample pretreatment. Pesticide extraction from different sample matrices was carried out on Chromabond C₁₈ cartridges using 3.0 mL of methanol and 3.0 mL of a mixture of dichloromethane/acetonitrile (1:1 v/v) as the eluting solvent. Analysis was carried out by gas chromatography coupled with mass spectrometry using selected‐ion monitoring mode. Good linear relationships were obtained in the range of 0.1–50 μg/L for chlorpyrifos, and 0.05–50 μg/L for both malathion and diazinon pesticides. Good repeatability and recoveries were obtained in the range of 78.54–86.73% for three pesticides under the optimized experimental conditions. The limit of detection ranged from 0.02 to 0.03 μg/L, and the limit of quantification ranged from 0.05 to 0.1 μg/L for all three pesticides. Finally, the developed method was successfully applied for the determination of three targeted pesticides in milk, apples, and drinking water samples each in triplicate. No pesticide was found in apple and milk samples, but chlorpyrifos was found in one drinking water sample below the quantification level.     

在线固相萃取-超高效液相色谱-三重四极杆质谱法测定水源水和饮用水中107种典型农药及代谢产物

为进行我国水体中农药风险监测,针对水体中农药种类多、浓度低的特点,建立了在线固相萃取-超高效液相色谱-串联质谱法快速筛查和检测水源水及饮用水中107种典型农药及代谢产物(有机磷类、有机氮类、有机杂环类、氨基甲酸酯类、酰胺类、苯甲酰脲类、新烟碱类等)的方法。样品经0.22 μm孔径亲水性聚四氟乙烯滤膜过滤后,通过自动进样器取5 mL样品注入在线固相萃取系统,经X Bridge C₁₈在线固相萃取柱吸附后用纯水淋洗,以乙腈和0.1%甲酸水溶液为流动相对在线固相萃取柱梯度洗脱后再经ACQUITY HSS T₃色谱柱分离,采用电喷雾离子源正离子及负离子模式分析检测,外标法定量。以水源水及饮用水作为基质,对其准确度和精密度进行方法学验证,结果表明:107种农药及代谢产物在不同范围内线性关系良好(r²>0.995),方法检出限(LOD, S/N=3)为0.03~1.5 ng/L,定量限(LOQ, S/N=10)为0.1~5.0 ng/L。将目标分析物在1、20、50 ng/L水平下加标,水源水和饮用水中的加标回收率分别为60.6%~119.8%和61.2%~119.0%,相对标准偏差(RSD, n=6)分别为0.3%~18.6%和0.4%~17.1%。用该方法测定水源水和饮用水中的农药残留,结果显示,酰胺类、三嗪类除草剂、三唑类杀菌剂与烟碱类、氨基甲酸酯类杀虫剂有较高的检出率,其中水源水中检出含量为0.1~97.1 ng/L,饮用水中检出含量为0.1~93.6 ng/L。该方法适用于水源水和饮用水中107种典型农药及代谢产物的痕量分析测定,有效提高了水体中农药类物质的检测效率,实际应用价值较高。     

Determination of 24 pesticides residues in mineral and peat soils by modified QuEChERS method and gas chromatography

A simple extraction and cleanup procedure has been developed for the analysis of 24 organophosphorus (OP), organochlorine (OC) and pyrethroid (PY) pesticides in mineral and peat soils using modified QuEChERS method. The pesticides were extracted from the soil with acidified acetonitrile. The water was removed from the extract by salting out with sodium chloride and addition of magnesium sulfate. For OP pesticides, the extracts were cleaned up with 0.2 g of primary secondary amine packed in glass Pasteur pipette and determined by gas chromatography with flame photometric detector. For OC and PY pesticides, the extracts were cleaned up with 0.2 g of silica gel packed in a glass Pasteur pipette and determined by gas chromatography with electron capture detector. After the cleanup, the extracts had lower colour intensity and reduced matrix interferences. The recovery of the OP and OC pesticides for mineral and peat soils determined at 0.01–1.0 mg kg^?1 fortification levels ranged from 79.0–120.0% and 82.2–117.6%, respectively. The detection limits for OP and OC pesticides were 0.001–0.01 and 0.002–0.005 mg kg^?1, respectively. The recovery of the PY pesticides ranged from 87.5–111.7% at the detection limits of 0.002–0.010 mg kg^?1. The relative standard deviations for all pesticides studied were below 10.8%. The modified method was simple, fast, and had utilized less reagents than the conventional methods. The method was applied to the determination of the pesticide residues in mineral and peat soil samples collected from the vegetable farms.     

Determination of Organophosphorus Pesticides in Leeks (Allium porrum L.) by GC-FPD

A method was validated for the analysis of organophosphorus pesticides in leeks. The leek sample was cut into about 2 cm lengths and heated in a microwave oven for 50 s to inactivate enzymes. The sample was extracted with 50 mL acetonitrile using an Ultra-turrax T18 blender and cleaned up by solid phase extraction. The target analytes were determined by GC with a flame photometric detector. Average recoveries were 73–118% and limits of detection ranged from 1.1 to 10.0 μg kg^?1. The uncertainty of the analysis for each pesticide was evaluated as below 16%. The method was applied to determine organophosphorus pesticides in real samples. The GC–MS was used as confirmatory tool for positive samples.     

超高效液相色谱-串联质谱法测定白芷中51种禁用农药的残留量

将白芷药材粉碎至通过孔径为(250±9.9)μm的网筛,并称取此白芷粉末样品2.00g于聚丙烯管中与水10mL混匀,再加入含1%(体积分数)乙酸的乙腈10.0mL,涡旋1min后加入无水硫酸镁4g和乙酸钠1g,剧烈振荡3min,离心5min,取其上清液5.0mL置于已盛有无水硫酸镁900mg、N-丙基乙二胺(PSA)450mg和硅胶300mg的净化管中,剧烈振荡5min使净化完全,离心5min。移取上清液3.0mL于40℃水浴中减压蒸缩至近干。加入50μg·L^-1的磷酸三苯酯内标溶液300μL,加入乙腈定容至1.0mL,经0.20μm滤膜过滤,取其滤液,按仪器工作条件进行超高效液相色谱-串联质谱法分析。选用Eclipse Plus C18色谱柱和以不同比例的(A)含10mmol·L^-1甲酸铵的0.1%(体积分数)甲酸溶液和(B)乙腈的混合液为流动相,按梯度洗脱程序对白芷中可能残留的51种禁用农药进行色谱分离,并在电喷雾离子源正、负离子(ESI+和ESI-)电离方式和动态多反应监测(dMRM)模式条件下进行串联质谱法测定。采用基质匹配标准曲线法定量。51种农药的质量浓度在一定范围内与其对应的峰面积呈线性关系,并测得其检出限(3S/N)为0.3~5.0μg·kg^-1。标准加入法回收试验的结果显示,其中大部分农药的回收率在71%以上,测定值的相对标准偏差(n=6)均小于20%。按此方法分析了70批白芷样品,共检出16种农药,其中甲拌磷亚砜的检出率达95%,最高检出量为15.2μg·kg^-1;甲拌磷砜和毒死蜱的检出率均为10%,最高检出量依次为3.5,45.0μg·kg^-1,其余13种农药的检出率均低于5%,且检出量均较低。     

Determination of nitroimidazole residues in porcine urine by liquid chromatography/tandem mass spectrometry

A reliable and sensitive method was developed for determination of nitroimidazoles in porcine urine. Sample preparation involves an extraction with ethyl acetate, followed by a solid-phase extraction cleanup step. The final extract is injected into the liquid chromatography/tandem mass spectrometry system in the positive-ion electrospray ionization mode. A C8 column with water and acetonitrile as the mobile phase is used for chromatographic separation under gradient conditions. Overall average recoveries ranged from 83 to 107%. The limits of detection ranged from 0.03 to 0.05 ng/mL, and the limits of quantitation, from 0.1 to 0.2 ng/mL.     

A solid phase extraction method for the screening and determination of pyrethroid metabolites and organochlorine pesticides in human urine.

A screening method has been developed for the determination of 23 organochlorine pesticides (OCPs) and 3-pyrethroid metabolities [cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid, cis-3-(2,2-dibromovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid and 3-phenoxybenzoic acid] from human urine. OCPs were directly detected in urine samples while pyrethroid metabolites required acid-induced hydrolysis to convert their conjugates into free acids; all compounds were then cleaned-up/preconcentrated using solid phase extraction. Determination and quantitation was achieved by gas chromatography with a mass spectrometer detector operating in selected ion monitoring mode. Limits of detection varied between 0.1 and 0.3 ng/mL with linear ranges from 0.3 to 700 ng/mL; the precision of the method was high (4.3-7.2%). Recoveries of all analytes from urine samples fortified at levels of 30 ng/mL for each OCP and 15 ng/mL for each pyrethroid metabolite ranged from 88 to 101% (captan gave the lowest recovery). The results obtained from the analysis of real urine samples show the suitability of the proposed method for monitoring people exposed to organochlorine and pyrethroid pesticides.     

超高效液相色谱-三重四极杆质谱法测定人尿中9种邻苯二甲酸酯代谢物

建立了人尿中9种邻苯二甲酸酯（PAE）代谢物的超高效液相色谱-三重四极杆质谱（UPLC-MS/MS）测定方法。2 mL尿液样本酶解2 h后,经强阴离子固相萃取净化处理;选用Waters ACQUITY UPLC BEH Phenyl色谱柱（100 mm×2.1 mm,1.7 μ m）,以0.1%（体积分数）乙酸乙腈和0.1%（体积分数）乙酸水溶液为流动相进行梯度洗脱;在负离子电喷雾多反应监测模式（MRM）下测定9种PAE代谢物含量。8种PAE代谢物在0.39~200 μ g/L范围内、1种PAE代谢物在1.17~600 μ g/L范围内线性关系良好,相关系数均大于0.995。方法检出限为0.06~0.85 μ g/L,定量限为0.20~2.80 μ g/L。3个加标水平的加标回收率为84.1%~122%,精密度为4.5%~14.3%;日内精密度不高于9.3%,日间精密度不高于10.1%;基质效应和稳定性符合分析要求。应用该方法测定50份人尿液样本,邻苯二甲酸单环已酯（MCHP）和邻苯二甲酸单苄酯（MBZP）的检出率分别为0和44.0%,其余7种PAE代谢物的检出率为100%。该方法操作简单、定量准确、稳定性好,适用于人尿中9种PAE代谢物的定量分析。     

Ultra-Preconcentration and Determination of Multiple Pesticide Residues in Water Samples Using Ultrasound-Assisted Dispersive Liquid–Liquid Microextraction and GC-FID

In this study, a simple and efficient method has been developed to analyze pesticides in water samples using ultrasonic-assisted dispersive liquid–liquid microextraction (UA-DLLME) combined with gas chromatography-flame ionization detection (GC-FID). Several parameters, including type and volume of extractant and dispersant, extraction time, and amount of salt on extraction performance, were optimized in detail. A mixture of acetonitrile (1.0 mL, dispersant) and carbon tetrachloride (15 μL, extractant) was used for extraction. Under optimal conditions, enrichment factors were obtained between 315 and 1153. The linearity of the method ranged from 1 to 100 μg L⁻¹ with correlation coefficients ≥0.9990. Limits of detection (S/N = 3) ranged between 0.09 and 0.57 μg L⁻¹, depending on the compounds. Relative standard deviations were <8.0 % (n = 5) for both intra- and inter-day analyses. The proposed method was successfully applied for the preconcentration and determination of pesticides in water samples (river water, tap water, and lake water) with recoveries that varied from 90.5 to 107.7 %.

     

Ultra-Preconcentration and Determination of Multiple Pesticide Residues in Water Samples Using Ultrasound-Assisted Dispersive Liquid–Liquid Microextraction and GC-FID

In this study, a simple and efficient method has been developed to analyze pesticides in water samples using ultrasonic-assisted dispersive liquid–liquid microextraction (UA-DLLME) combined with gas chromatography-flame ionization detection (GC-FID). Several parameters, including type and volume of extractant and dispersant, extraction time, and amount of salt on extraction performance, were optimized in detail. A mixture of acetonitrile (1.0 mL, dispersant) and carbon tetrachloride (15 μL, extractant) was used for extraction. Under optimal conditions, enrichment factors were obtained between 315 and 1153. The linearity of the method ranged from 1 to 100 μg L^?1 with correlation coefficients ≥0.9990. Limits of detection (S/N = 3) ranged between 0.09 and 0.57 μg L^?1, depending on the compounds. Relative standard deviations were <8.0 % (n = 5) for both intra- and inter-day analyses. The proposed method was successfully applied for the preconcentration and determination of pesticides in water samples (river water, tap water, and lake water) with recoveries that varied from 90.5 to 107.7 %.     

Simultaneous analysis of six inorganic anions in urine by double-suppress ion-exchange chromatography

This study is aimed to establish a simple, rapid, and accurate ion chromatography approach for the simultaneous detection of six inorganic anions in urine. Various performance parameters affecting the determination of anions were optimized, including the selection of sample protein precipitation agent, eluent, and flow rate. The final eluent was 3.6 mmol/L sodium carbonate and 12% isopropanol with a flow rate of 0.6 mL/min. Acetonitrile was used for pretreatment to precipitate proteins, and the volume ratio of urine to acetonitrile was 1:4. The correlation coefficient of the target anion calibration curve ranged from 0.9973 to 0.9999. The limit of detection ranged from 1.50 to 12.0 μg/L, and the method detection limit ranged from 15.0 to 120 μg/L. The standard recovery rate for low, medium, and high concentrations ranged from 90 to 110%. The inter-day and intra-day relative standard deviations were <5%. The method has high accuracy and good reproducibility and is suitable for the separation and determination of anions in urine.     

Detection of organophosphate pesticides in human body fluids by headspace solid-phase microextraction (SPME) and capillary gas chromatography with nitrogen-phosphorus detection

Summary Organosphosphate pesticides have been found extractable by headspace solid-phase microextraction (SPME), and the best conditions of their extraction from human whole blood and urine samples have been investigated. The body fluid samples containing nine pesticides (IBP, methyl parathion, fenitrothion, malathion, fenthion, isoxathion, ethion, EPN and phosalone) were heated at 100°C in a septum-capped vial in the presence of various combinations of acid and salts, and SPME fiber was exposed to the headspace of the vial to allow adsorption of the pesticides before capillary gas chromatography (GC) with nitrogen-phosphorus detection. The heating with distilled water/HCl/(NH₄)₂SO₄/NaCl and with distilled water/HCl gave the best results for urine and whole blood, respectively. Recoveries of the nine pesticides were 0.8–10.6% except for phosalone (0.03%) for whole blood, and 3.8–40.2% for urine. The calibration curves for the pesticides showed linearity in the range of 50–400 ng/0.5 mL for whole blood except for malathion (100–400 ng/0.5 mL whole blood) and 7.5–120 ng/0.5 mL for urine except for phosalone (15–120 ng/0.5 mL urine) with detection limits of 2.2–40 ng/0.5 mL for whole blood and 0.8–12 ng/0.5 mL for urine.     

Determination of pesticides originating from golf courses by solid-phase extraction and liquid chromatography-tandem mass spectrometry

A multi-residue method using liquid chromatography coupled to triple quadrupole tandem mass spectrometry (LC-MS/MS), associated with solid-phase extraction (SPE), was developed for the determination of 21 pesticides in water samples. The compounds investigated are used for the maintenance of golf courses and ordinarily measured by gas chromatography-mass spectrometry (GC-MS). Electrospray ionisation (ESI) was applied to all compounds, and LC and MS conditions were optimised to measure them under SRM mode. This method showed excellent linearity ranges for all pesticides, with correlation coefficients greater than 0.996. Two kinds of extraction cartridges, namely, styrene divinylbenzene polymer (Sep-Pak PS-2) and divinylbenzene-N-vinylpyrrolidone copolymer (Oasis HLB), were tested and the extraction conditions were optimised. All the pesticides were determined using acetonitrile and ethyl acetate as eluents in both cartridges, and good recoveries (>77%) and repeatability with low relative standard deviations (RSDs, <12%) were achieved from ultra-pure water. In addition, satisfactory recoveries (>76%) and low intra-day and inter-day RSDs (<15%) of all pesticides were also obtained with the Sep-Pak PS-2 cartridge when using river water. The method limits of detection (LODs) ranged between 0.068 (diazinon) and 3.9 (triclopyrbutoxyethyl)?ng?L^?1. The analytical method was successfully applied for the determination of pesticides in surface river water.