气相色谱-负化学源质谱法测定蔬菜中17种拟除虫菊酯类农药残留量

建立了气相色谱-负化学源质谱检测蔬菜中17种拟除虫菊酯类农药残留量的方法。样品中的目标物经乙腈提取后,用乙二胺-N-丙基甲硅烷(PSA)和石墨化炭黑填料进行分散固相萃取净化,气相色谱-负化学源质谱选择离子监测模式测定,同位素内标法定量。在甜豌豆、绿花菜和大葱基质中均未见干扰所有农药测定的现象。17种拟除虫菊酯类农药的定量限均为0.02～5 μg/kg。在10、20、30和100 μg/kg等4个添加水平下,所有农药的回收率均为71.0%～139.0%,相对标准偏差≤12.8%。该方法可作为蔬菜中17种菊酯类农残检测的确证方法。     

多壁碳纳米管固相萃取净化气相色谱法分析蔬菜中有机氯和拟除虫菊酯农药残留

建立了多壁碳纳米管为吸附剂的固相萃取(SPE)净化、气相色谱-电子捕获检测(GC-ECD)测定蔬菜中6种有机氯和7种拟除虫菊酯农药的方法。采用双柱(HP-50和HP-1色谱柱)双检测器进行定性和定量分析。蔬菜样品采用乙腈提取,多壁碳纳米管SPE柱净化,正己烷溶解上样,丙酮-正己烷(7:3, v/v)洗脱,13种农药中有11种农药的添加回收率高于70%。将该净化方法用于荷兰黄瓜、卷心菜、红圣女果、奶油生菜、紫甘蓝、韭菜、大葱和洋葱等样品的净化,与弗罗里硅土SPE柱相比较,净化效果更好,表明多壁碳纳米管具有较强的吸附去除色素的能力,可以避免色素对测定的干扰。     

高效液相色谱法同时测定蔬菜水果中的12种农药残留

建立了同时测定蔬菜水果中12种农药残留的反相高效液相色谱分析方法。将样品捣碎,用乙酸乙酯超声提取,经Florisil固相萃取柱净化、正己烷-二氯甲烷(体积比为1∶1)洗脱、氮气吹干、甲醇溶解并定容后,采用高效液相色谱柱分离、紫外检测,以外标法定量。结果表明：12种农药标准曲线的线性相关系数范围为0.9985~0.9999;检测限为0.14~2.65 ng;在水果中的平均加标回收率为62.2%~118.2%,相对标准偏差(RSD)为0.56%~11.8%;在蔬菜中的平均加标回收率为52.1%~124.6%,RSD为0.89%~18.4%。用所建立的方法成功地测定了白菜、莲白、黄瓜、苹果、梨等40份样品中的农药残留。方法具有快速、简便、准确、灵敏、重现性较好的特点,适合于蔬菜水果样品中多种微量农药残留的测定。     

Interlaboratory study of a multiresidue gas chromatographic method for determination of organochlorine and pyrethroid pesticides and polychlorobiphenyls in milk,fish, eggs,and beef fat

An interlaboratory study was conducted to validate a gas chromatographic (GC) method for determination of 21 organochlorine pesticides, 6 pyrethroid pesticides, and 7 polychlorobiphenyl (PCB) congeners in milk, beef fat, fish, and eggs. The method was performed at low contamination levels, which represent relevant contents in food, and is an extension of the European standard (method NF-EN-1528, Parts 1-4). It enlarges the applicable scope of the reference EN method to pyrethroid pesticides and proposes the use of solid-phase extraction (SPE) as a cleanup procedure. Cryogenic extraction was made, and SPE cleanup was performed with 2 successive SPE cartridges: C18 and Florisil. After injection of the purified extract onto a GC column, residues were measured by electron capture detection. Food samples (liquid milk, beef fat, mixed fish, and mixed eggs) were prepared, tested for homogeneity, and sent to 17 laboratories in France. Test portions were spiked with 27 pesticides and 7 PCBs at levels from 26 to 45, 4 to 27, 31 to 67, and 19 to 127 ng/g into milk, eggs, fish, and fat, respectively. Based on results for spiked samples, the relative standard deviation for repeatability ranged from 1.5 to 6.8% in milk, 3 to 39% in eggs, 4.5 to 12.2% in fish, and 7 to 13% in fat. The relative standard deviation for reproducibility ranged from 33 to 50% in milk, 29 to 59% in eggs, 31 to 57% in fish, and 30 to 62% in fat. This method showed acceptable intra- and interlaboratory precision data, as corroborated by HORRAT values at low levels of pesticide and PCB contamination. The statistical evaluation of the results was performed according to the International Organization for Standardization (ISO; ISO 3534 standard) and 5725-2 Guideline.     

加速溶剂萃取-超高效液相色谱-串联质谱法测定茶叶中拟除虫菊酯类农药残留

建立了加速溶剂萃取（ASE）-超高效液相色谱（UPLC）-串联质谱法（MS/MS）测定茶叶中拟除虫菊酯类农药残留的方法。ASE萃取温度为80 ℃，萃取压力为10.34 MPa，以正己烷-丙酮（2∶1，v/v）为溶剂静态萃取5 min，循环一次。萃取液浓缩后经GCB/NH₂-Florisil柱净化，UPLC分离，MS/MS正离子扫描（ESI⁺）、多反应离子监测（MRM）模式进行分析，外标法定量。线性回归分析表明：10种拟除虫菊酯的浓度与其峰面积的线性关系显著，相关系数（r）均不小于0.9995，检出限（LOD）在0.5~5.0 μg/kg之间，定量限（LOQ）在1.6~16.6 μg/kg之间；在定量限、0.4 mg/kg以及最高残留限量（MRL，无MRL的加入1 mg/kg）3个水平进行添加回收试验（n=7），回收率为68.7%~103.8%，RSD为0.8%~13.2%。该方法前处理简单，耗时短，灵敏度和准确度高，可满足茶叶中痕量拟除虫菊酯类农药残留测定的要求。     

Analysis of pyrethroid pesticides in Chinese vegetables and fruits by GC–MS/MS

A rapid and economical method using modified QuEChERS sample pretreatment coupled with high-sensitivity gas chromatography/triple quadrupole mass spectrometry was established to simultaneously determine ten pyrethroid pesticides in fruits and vegetables. All pesticides were detected within 20 min of one injection. Concurrent backflushing provided column protection, greatly facilitating instrument maintenance. For quantitation, matrix-matched calibration was used to compensate for signal-enhancement effects and to ensure the precision of the method. The limit of detection (LOD) was in the range of 0.3–4.9 μg/kg. The recovery rate was from 78.8 to 118.6%, with relative standard deviation (RSD) below 14.8%. The developed method is suitable for rapid and sensitive multi-residue analysis of pyrethroid pesticides in fruits and vegetables. It is good for users in professional institutions that implement safety controls for testing hundreds of agricultural product samples everyday.     

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.     

亚临界水萃取及气相色谱-串联质谱法检测红茶中多种农药残留

建立了亚临界水萃取及气相色谱-串联质谱(GC-MS/MS)检测红茶中21种有机氯和拟除虫菊酯农药残留的方法。在萃取压力为5 MPa条件下,样品经150 ℃的亚临界水提取15 min后,将目标物转移至丙酮-正己烷(1:1, v/v)中,经ENVI-Carb固相萃取净化小柱净化,DB-5毛细管气相色谱柱分离,在多反应监测(MRM)模式下进行MS/MS检测,基质匹配溶液内标法定量。各目标物在5.0～320.0 μg/L范围内线性关系良好,相关系数均大于0.99,其定量限(信噪比(S/N)＞10)为50 ng/g,检出限(S/N＞3)为10 ng/g。茶叶基质中添加50、100和200 ng/g的标准品时,21种农药的回收率为70.18%～119.98%,相对标准偏差(RSD)为5.01%～11.76%。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,适用于红茶中有机氯和拟除虫菊酯农药残留的检测。     

固相萃取-超快速液相色谱-串联质谱法测定当归中135种农药及其代谢物残留

建立了超快速液相色谱-串联质谱(UFLC-MS/MS)同时测定当归药材中135种农药及其代谢物(包括有机磷类、氨基甲酸酯类、拟除虫菊酯类农药等)残留量的分析方法。以回收率为考察指标,评估了不同的提取溶剂、固相萃取小柱、洗脱溶剂及体积对当归中多农残的提取净化效果,最终确定样品经乙腈提取,PSA固相萃取柱净化处理,在电喷雾正离子扫描、依赖保留时间的多反应监测模式(scheduled MRM)下,以基质匹配校准曲线内标法定量。结果表明,135种农药及其代谢物在各自的浓度范围内线性关系良好(r>0.99); 3个添加水平(10、50、100 μg/kg)下,除了烯草酮回收率偏低(62.0%~68.2%)外,其余农药的回收率为71.3%~119.7%,相对标准偏差(RSD, n=6)不大于19.9%, 135种农药及其代谢物的定量限为1.0~10.0 μg/kg。该方法样品前处理简单、快速、灵敏,可用于当归药材中多类别农药残留量的定性、定量。     

液相色谱-串联质谱法测定10种食品中四溴菊酯残留

建立了测定蔬菜、水果、茶叶、大豆等10种食品中四溴菊酯残留的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品以乙酸乙酯(蔬菜、水果、茶叶样品)或乙腈(大豆样品)为提取剂,上层有机相经浓缩、固相萃取小柱净化,流动相定容后,采用HPLC在Agilent ZORBAX Eclipse XDB C18色谱柱上,以甲醇和缓冲盐溶液(0.1%甲酸-10 mmol/L乙酸铵)为流动相进行梯度洗脱分离,以串联质谱在多反应监测(MRM)模式下测定,基质外标法定量。结果表明,四溴菊酯的质量浓度在20～1 000μg/L范围内线性关系良好,相关系数为0.999 8;在0.01、0.02、0.1 mg/kg(粮谷类、茶叶、大豆样品)和0.005、0.01、0.05mg/kg(果蔬类样品)加标水平下的回收率为75%～92%,相对标准偏差(RSDs)为4.0%～12.6%(n=6),定量下限(S/N≥10)为0.01 mg/kg(粮谷类、茶叶、大豆样品)和0.005 mg/kg(果蔬类样品)。该方法不受溴氰菊酯干扰,可直接测定四溴菊酯,克服了以往方法只能测定四溴菊酯和溴氰菊酯总量的不足。     

快速气相色谱法测定蔬菜中菊酯类农药残留量

采用一种较快速，简单的方法测定蔬菜中菊酯类农药残留物。样本中农残经乙酸酯萃取，凝胶渗透色谱及固相提取净化后，用气相色谱－电子捕获检测器测定，色谱柱为ＨＰ－５小口长石英毛细管柱。本法对６种常用菊酯类农药的回收率范围为８９．６％－９９．７％，检测限为０．０４ｍｇ／ｋｇ。对同一批普施用菊酯类农药的白菜样本进行化验，本法跟美国食物及药品管理局农药残留标准测定方法所得结果非常吻合。     

Multiresidue gas chromatographic method for determining synthetic pyrethroid pesticides in agricultural products: collaborative study

Fourteen laboratories from 6 countries and regions participated in an international collaborative study to evaluate a multiresidue gas chromatographic (GC) method for determining 8 synthetic pyrethroid pesticides in grains, fruits, and vegetables. The study design was based on Youden's matched-pairs principle for collaborative tests of analytical methods. Each laboratory analyzed 12 collaborative samples of wheat, oranges, and tomatoes as blind samples. Wheat samples were extracted with acetonitrile-water (2 + 1), while orange and tomato samples were extracted with acetone. Residues were partitioned into hexane, evaporated to dryness with a rotary evaporator, and then dissolved in hexane. The hexane extract was partitioned with acetonitrile and cleaned up on a 5% water-deactivated Florisil column with 6% ethyl ether in hexane as eluant. Residue concentrations were determined by GC with electron capture detection with splitless injection by comparison with single-point calibration standards. The appropriate standard concentration was determined by screening sample extracts before analysis. The multiresidue method was tested over the concentration range of 0.095-1.909 mg/kg depending on the 8 different of pesticides and agricultural products analyzed in the collaborative study. Statistical analysis of data from 13 laboratories showed weighted average recoveries for 8 pyrethroids in wheat, oranges, and tomatoes at 0.105-1.909, 0.095-1.909, and 0.105-0.954 mg/kg, respectively, ranging from 91.8 to 100.2%, from 88.1 to 100.6%, and from 88.2 to 101.5%, respectively. Reproducibility relative standard deviation values ranged from 6.46 to 17.74%, from 5.94 to 18.13%, and from 5.59 to 10.48%, respectively. Repeatability relative standard deviation values ranged from 6.34 to 10.84%, from 5.19 to 11.72%, and from 3.20 to 8.09%, respectively. The multiresidue GC method for determining synthetic pyrethroid pesticides in agricultural products has been adopted first action by AOAC INTERNATIONAL.     

一种富集海水中有机氯和菊酯类农药的船载式正压固相萃取装置

研制了一种正压驱动的新型固相萃取(SPE)装置以替代真空泵负压驱动SPE装置用于富集海水中的有机氯和菊酯类农药。与水样接触的采样瓶和管路均采用不含氯的塑料材质。整个装置的连接部分用螺母螺栓紧固,以保证密封性和牢固性。水样瓶内部的压力(0.1~0.3 MPa)由单片机和压力传感器控制的隔膜充气泵(12 V电池供电)提供,水样过柱的流速在4.0~6.0 mL/min之间。SPE柱预淋洗后储存4周内有效,采样后储存6周内回收率大于80%。方法的线性关系良好,相关系数均大于0.9,方法的定量限为0.8~6.0 ng/L,3个不同添加水平(n=3)的平均回收率为86.1%~95.5%,相对标准偏差小于10%。海水实际样品中均检出六六六(BHC)和滴滴涕(DDT)。该装置在富集海水中有机氯和菊酯类农药方面有较好的应用。     

Applications of LC/ESI-MS/MS and UHPLC QqTOF MS for the determination of 148 pesticides in fruits and vegetables

This paper presented the applications of liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) and ultra-high-pressure liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC QqTOF MS) for the determination of 148 pesticides in fruits and vegetables. Pesticides were extracted from fruits and vegetables using a buffered QuEChERS method. Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analog as internal standards in an analytical range from 5 to 500 μg/kg. The method performance parameters including overall recovery, intermediate precision, and measurement uncertainty were evaluated according to a statistically designed experiment, i.e., a nested design. For LC/ESI-MS/MS, 95% of the pesticides had recoveries between 81% and 110%; 97% had an intermediate precision ≤20%; and 95% (in fruits) or 93% (in vegetables) showed measurement uncertainty ≤40%. Compared to LC/ESI-MS/MS, UHPLC QqTOF MS showed a relatively poor repeatability and large measurement uncertainty. About 93% (in fruits) or 94% (in vegetables) of the pesticides had recoveries between 81% and 110%; 86% (in fruits) or 90% (in vegetables) had an intermediate precision ≤20%; and 79% (in fruits) or 88% (in vegetables) showed measurement uncertainty ≤40%. LC/ESI-MS/MS proved to be the first choice for quantification or pre-target analysis due to its superior sensitivity and good repeatability. UHPLC QqTOF MS provided accurate mass measurement and isotopic patterns, and was an ideal tool for post-target screening and confirmation.     

Fe3O4纳米粒子修饰多壁碳纳米管的制备及在水和蜂蜜样品中痕量菊酯类农药分析中的应用

通过化学共沉淀法使Fe₃O₄纳米粒子负载于酸化多壁碳纳米管(AMWNTs)表面,得到Fe₃O₄/AMWNTs磁性纳米材料。该材料具有很好的磁响应度和分散性,将其用于富集痕量拟除虫菊酯类农药残留,结果证明该复合材料对菊酯类农药的吸附性能良好。通过对影响萃取性能的几种因素如离子强度、萃取时间和解吸时间依次进行优化,在最优条件下,建立了Fe₃O₄/AMWNTs磁性分散固相萃取-气相色谱测定6种菊酯类农药残留的分析方法。线性范围在0.5~50 μg/L之间,相关系数(R²)大于0.990,检出限为0.07~0.20 μg/L,精密度为3.8%~8.1%。该方法用于河水、鱼塘水和两种市售蜂蜜中菊酯类农药的残留分析,回收率高于78.4%。该方法操作简便、灵敏度高,能够满足环境水样及蜂蜜样品中痕量菊酯农药残留的分析需求。     

Rapid analysis of pyrethroid insecticides in aquaculture seawater samples via membrane-assisted solvent extraction coupled with gas chromatography-electron capture detection

A simple, efficient, and environmentally friendly membrane-assisted solvent extraction (MASE) method for the extraction and preconcentration of six pyrethroid insecticides from aquaculture seawater samples followed by gas chromatography-electron capture detection (GC-ECD) was successfully proposed. The operating conditions for MASE, such as the extraction solvent, solvent volume, NaCl concentration, stirring rate, extraction time, and temperature, were optimized. Compared to conventional Florisil-solid phase extraction (SPE), higher extraction recoveries (85.9% to 105.9%) of three spiked levels of the six pyrethroid pesticides in aquaculture seawater were obtained using MASE, and the RSD values were lower than 7.9%. The limits of detection (LOD, signal-to-noise ratio (S/N)=3) and quantification (LOQ, S/N = 10) were in the range of 0.037-0.166 and 0.12-0.55 μg L(-1), respectively. The results demonstrate the excellent applicability of the MASE method in analyzing the six pyrethroid pesticides in aqueous samples. The proposed method exhibited a high potential for routine monitoring analysis of pyrethroid insecticides in seawater samples.     

加速溶剂萃取/凝胶渗透色谱－固相萃取净化、气相色谱－质谱法测定茶叶中残留的33种农药

建立了茶叶中有机磷、有机氯、拟除虫菊酯类共33种农药残留的分析方法。样品以丙酮-二氯甲烷(体积比为1:1)为提取剂经加速溶剂方法萃取,提取液用凝胶渗透色谱净化除去大部分的色素、脂类和蜡质,再用Carb-NH2小柱和Florisil小柱净化。采用气相色谱法分析、外标法定量、气相色谱-质谱法（GC-MS）定性。加标水平为0.05 mg/kg时,大部分农药的回收率为70%~120%,相对标准偏差小于20%。方法的检测限为0.005～0.05 mg/kg (以10倍信噪比计)。该方法的提取效率高,准确灵敏,目前已应用于出口茶叶中农药残留的日常检测。大量实际样品的检测结果表明,此方法适于出口茶叶中农药残留检测实际工作的需要。     

The high throughput analysis of N-methyl carbamate pesticides in fruits and vegetables by liquid chromatography electrospray ionization tandem mass spectrometry using a short column

We developed a new analysis method for the nine N-methyl carbamate pesticides in fruits and vegetables using ESI LC/MS/MS with direct sample injection into a short column. After extraction of the pesticides with ethyl acetate from sample, the extract is evaporated to dryness and redissolved in ultra pure water before injection into LC/MS/MS. The method needs no cleanup steps. The average recoveries from fruits and vegetables fortified at the level of 0.01 μg/g ranged from 56.0 to 119.1% with the coefficients of variation ranging from 0.2 to 7.6% for intra-day (n = 5 × 3 days) and from 0.8 to 18.4% for inter-day (n = 15). At the fortified level of 0.5 μg/g, the recoveries ranged from 67.7 to 119.3% with the coefficients of variation ranging from 0.5 to 7.8% for intra-day (n = 5 × 3 days) and from 0.9 to 14.8% for inter-day (n = 15). The method is considered to be satisfactory for the monitoring of the carbamate pesticide residues in fruits and vegetables, suggesting that the present method is applicable to other pesticide residues in foods.     

固相萃取-三重串联四极杆气相色谱/质谱联用分析蔬菜中43种农药残留留

建立了气相色谱/三重四极杆串联质谱同时分析蔬菜中43种农药残留的方法。采用乙腈提取样品中待测组分,经固相萃取法(SPE)净化后采用气相色谱/三重四极杆串联质谱在多反应监测(MRM)模式下进行外标法定量测定。分别对青菜进行3个水平(10、80、200 μg/kg)的加标回收试验,其回收率为62.2%～170.0%,其中36种农药的回收率为70.0%～120.0%。方法的相对标准偏差(RSD)小于18%,定量限(LOQ)为0.3～4.4 μg/kg。该分析方法背景干扰低,灵敏度高,适合蔬菜中多种农药及杀虫剂残留的测定。     

Determination of seventeen polar/thermolabile pesticides in apples and apricots by liquid chromatography/mass spectrometry

A simple liquid chromatography/mass spectrometry (LC/MS) approach for the determination of widely used representatives of polar/thermolabile pesticides in fruits was developed and validated. The group of pesticides comprised benzimidazoles and azoles (carbendazim, thiabendazole, imazalil, propiconazole, prochloraz, epoxiconazole, flusilazole, tebuconazole, bitertanol); N-methylcarbamates (carbaryl, carbofuran, methiocarb); and phenylureas and benzoylphenylureas (linuron, diflubenzuron, triflumuron, teflubenzuron, flufenoxuron). Matrixes (apple, apricot) were extracted with acetonitrile and crude extracts were cleaned up by solid-phase extraction (SPE) using either mixed cation exchange or hydrophilic lipophilic balance cartridges. LC separation of pesticides was performed on a reversed-phase column, Discovery C18. Electrospray ionization and ion trap MS/MS detection were applied. For most pesticides, overall recoveries ranged from 75 to 122%, and repeatability (as relative standard deviation) from 5 repetitive determinations of recovery ranged from 3 to 21%. Carbofuran was the only compound for which recovery was not satisfactory due to its loss in the SPE cleanup step. Limits of detection were 0.1-3 microg/kg for benzimidazole and azole fungicides and carbamate insecticides. For urea insecticides, detection limits were slightly higher (3-10 microg/kg).