微波辅助萃取-分散固相萃取-气相色谱质谱法测定茶叶中23种农药残留

建立了微波辅助萃取-分散固相萃取净化-气相色谱质谱法（GC-MS）快速测定茶叶中23种农药残留量的方法. 茶叶样品用乙腈进行微波辅助萃取（MAE）,提取液经分散固相萃取（DSPE）净化处理. 采用DB-17MS毛细管色谱柱分离后,选择离子监测模式下（SIM）质谱法进行测定. 23种农药组分在0.01~0.50 mg/mL质量浓度范围内呈线性关系,相关系数r2大于0.995,方法测定低限（10S/N）为0.005~0.01 mg/kg. 以空白绿茶为基体,在4个标准添加水平0.01、0.05、0.10、0.25 mg/kg进行加标回收试验,加标平均回收率为70%~105%,相对标准偏差为3.0%~8.2%.     

分散固相萃取-在线凝胶色谱-气相色谱-质谱联用法快速检测紫菜中的农药多残留

建立了紫菜中农药多残留的在线凝胶色谱-气相色谱-质谱联用（GPC-GC/MS）检测方法。以有机氯、有机磷、三嗪类和菊酯类的19种农药为目标物,对比了丙酮、丙酮/二氯甲烷（1:1,v/v）和乙腈3种有机溶剂的提取效果,通过石墨化炭黑粉（GCB）和N-丙基乙二胺粉（PSA）分散固相萃取净化和GPC在线净化,气相色谱-质谱联用法分析,外标法定量。结果表明,此方法实现了在线净化与分析检测的自动化,缩短了分析时间。分析物在10~1000 μg/L范围内线性关系良好,相关系数r>0.995;采取GPC大体积进样和气相色谱进样口的程序升温方式提高了检测灵敏度,检出限为0.005~0.03 mg/kg。方法的平均添加回收率在70%~120%之间,相对标准偏差（RSD）均小于15%。该方法简单、快速、具有良好的回收率和重复性,适用于紫菜样品中农药多残留的快速灵敏检测。     

Liquid chromatography-electrospray mass spectrometry multi-residue determination of pesticides in apples and pears

This paper describes a rapid, specific and sensitive multi-residue method for the routine quantitative analysis of pesticides of several classes used for the treatment of apples and pears, down to their respective maximum residue limits (MRLs). It involves a rapid extraction procedure and liquid chromatography coupled to electrospray mass selective detection. Seven pesticides were extracted at pH 4.5 with a mixture of acetone-dichloromethane-hexane (50:20:30, v/v/v). Ionization was performed at atmospheric pressure in an electrospray-type source and detection was carried out using the selected ion monitoring (SIM) mode. Extraction recoveries were between 55 and 98% except for methylthiophanate (< 20%). Limits of detection (LODs) and limits of quantitation (LOQs) ranged, respectively, from 0.01 to 0.02 mg/kg and from 0.02 to 0.05 mg/kg, with relative standard deviation (R.S.D.) less than 19%. An excellent linearity was observed for LOQs up to 5 mg/kg. Intermediate ("inter-assay") precision and accuracy were satisfactory. The method was applied to many fruit samples intended for commercialization.     

A fully automated system for analysis of pesticides in water: on-line extraction followed by liquid chromatography-tandem photodiode array/postcolumn derivatization/fluorescence detection.

A fully automated system for on-line solid phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) with tandem detection with a photodiode array detector and a fluorescence detector (after postcolumn derivatization) was developed for analysis of many chemical classes of pesticides and their major conversion products in aquatic systems. An automated on-line-SPE system (Prospekt) operated with reversed-phase cartridges (PRP-1) extracts analytes from 100 mL acidified (pH = 3) filtered water sample. On-line HPLC analysis is performed with a 15 cm C18 analytical column eluted with a mobile phase of phosphate (pH = 3)-acetonitrile in 25 min linear gradient mode. Solutes are detected by tandem diode array/derivatization/fluorescence detection. The system is controlled and monitored by a single computer operated with Millenium software. Recoveries of most analytes in samples fortified at 1 microgram/L are > 90%, with relative standard deviation values of < 5%. For a few very polar analytes, mostly N-methylcarbamoyloximes (i.e., aldicarb sulfone, methomyl, and oxamyl), recoveries are < 20%. However, for these compounds, as well as for the rest of the N-methylcarbamates except for aldicarb sulfoxide and butoxycarboxim, the limits of detection (LODs) are 0.005-0.05 microgram/L. LODs for aldicarb sulfoxide and butoxycarboxim are 0.2 and 0.1 microgram, respectively. LODs for the rest of the analytes except 4-nitrophenol, bentazone, captan, decamethrin, and MCPA are 0.05-0.1 microgram/L. LODs for the latter compounds are 0.2-1.0 microgram/L. The system can be operated unattended.     

超高效液相色谱-串联质谱法同时测定土壤中239种农药的残留量

建立了超高效液相色谱-串联质谱法(UPLC-MS/MS),可于10 min内快速测定土壤中的239种农药残留。土壤样品经AOAC (Association of Official Analytical Chemists) QuEChERS方法处理,用乙腈萃取;无水硫酸镁、乙酸钠固液分离后,过0.2 μm滤膜;在UPLC-MS/MS正、负离子同步扫描多反应监测模式下进行分析。239种农药中,线性相关系数(r²)大于0.99的有236个,占总数的99%。在40 μg/kg添加水平下所有被检测农药的回收率均在50%~150%之间,且相对标准偏差(RSD)均小于20%;其中有209种农药的回收率达到70%~120%,有161种的RSD小于10%。方法的检出限(LOD)范围为0.69~29.04 μg/kg。土壤中多种农药残留的同时检测要求时间短、准确度和精密度高,本方法符合这些检测要求,适用于土壤中农药残留的检测。     

加速溶剂萃取-凝胶渗透色谱净化-气相色谱快速分析动物源性食品中残留的多种有机磷农药

建立了动物源性食品猪肉、牛肉、鸡肉及鱼肉中36种有机磷农药残留的快速分析方法。以乙腈作为溶剂,对试样采用加速溶剂萃取仪萃取,自动凝胶渗透色谱仪净化预处理,N-丙基乙二胺(PSA)填料再净化,毛细管气相色谱法分离,火焰光度检测器(磷型)检测,内标法定量。该方法分离效果良好,重现性好,灵敏度、精密度高,杂质干扰少。36种有机磷农药的检测限(LOD)为0.0012 mg/kg(乙拌磷)～0.014 mg/kg(吡唑硫磷),定量限(LOQ)为0.004 mg/kg(乙拌磷)～0.047 mg/kg(吡唑硫磷)。当试样中有机磷农药的添加浓度分别为0.05,0.1,0.2 mg/kg时,回收率为58.2%～106.3%。方法的最低检测限和添加回收率均符合农药残留分析的要求。     

Determination of pesticide residues in complex matrices using multi-walled carbon nanotubes as reversed-dispersive solid-phase extraction sorbent

A modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method with multi-walled carbon nanotubes (MWCNTs) as a reversed-dispersive solid-phase extraction (r-DSPE) material combined with gas chromatography-mass spectrometry was developed for the determination of 14 pesticides in complex matrices. Four vegetables (leek, onion, ginger and garlic) were selected as the complex matrices for validating this new method. This technique involved the acetonitrile-based sample preparation and MWCNTs were used as the r-DSPE material in the cleanup step. Two important parameters influencing the MWCNTs efficiency, the external diameters and the amount of MWCNTs used, were investigated. Under the optimized conditions, recoveries of 78-110% were obtained for the target analytes in the complex matrices at two concentration levels of 0.02 and 0.2 mg/kg. In addition, the RSD values ranged from 1 to 13%. LOQs and LODs for 14 pesticides ranged from 2 to 20 μg/kg and from 1 to 6 μg/kg, respectively.     

Multiresidue analytical method of pesticides in peanut oil using low-temperature cleanup and dispersive solid phase extraction by GC-MS

A method for the determination of 33 pesticides in peanut oil by GC-MS was described. Two extraction procedures based on (i) low-temperature extraction and (ii) liquid-liquid extraction were tested for the optimization of the method. The mixture of anhydrous MgSO(4) with primary secondary amine (PSA) or with PSA and C(18) was performed as sorbents in dispersive SPE. Low temperature along with PSA and C(18) cleanup gave the best results. Pesticides were identified and quantified by GC-MS in SIM mode. The correlation coefficients, R(2), in the linear range tests were better than 0.990. The average recoveries for most pesticides (spiked at 0.02, 0.05, 0.2, and 1 mg/kg) ranged from 70 to 110%, the RSD was below 20% in most instances, and LODs varied from 0.5 to 8 mug/kg.     

Applicability of gradient liquid chromatography with tandem mass spectrometry to the simultaneous screening for about 100 pesticides in crops

A method was developed for screening crops for a range of pesticide residues by liquid chromatography/tandem mass spectrometry (LC/MS/MS). A complete set of LC, electrospray ionization (ESI), and tandem MS acquisition parameters was established for the determination of 108 analytes; these parameters were used for the simultaneous acquisition of 98 analytes in the positive ESI mode and 10 analytes in an additional MS/MS method in the negative ESI mode. The entire procedure involves extraction of residues with methanol-water and partition into dichloromethane. The utility of the method is demonstrated by the analysis of crops of 5 matrix types (water-containing, acidic, dry, sugar-containing, and fatty). Of 108 pesticides/metabolites tested, 104 showed sufficient stability in most matrixes for determination by LC/MS/MS. These analytes belong to 20 chemical classes, which demonstrate the general applicability of the method for multiclass analysis. By using matrix-matched standards, 67 compounds could be determined in most matrixes with recoveries of 70-120% and a relative standard deviation of < or = 25% at the 0.01 mg/kg level.     

Multi-residue analysis of pesticides in tea by online SEC-GC/MS

A multi-residue method for the analysis of pesticides in tea was developed by online size exclusion chromatography (SEC)-GC/MS with full scan mode. The sample was fortified with chlorpyrifos-d(10) isotope internal standard and extracted by acetonitrile. After purification by primary secondary amine sorbent and solvent exchange by SEC mobile phase, the sample was detected by online SEC-GC/MS. The purification result of the online system was evaluated by comparing the correlation between Chinese cabbage and tea matrix. The factors for method optimization included sample preparation, matrix effects and the instrument parameters of each online component. Scatter plot was introduced in this study to directly illustrate the results of the condition optimization and matrix effects in the online system. For most of the pesticides, the average recoveries ranged from 70 to 130% and the RSD were below 15%. The feasibility of the application of full scan mode in multi-residue determination of trace amounts of pesticides (LODs below 0.01 mg/kg) in a complex matrix was discussed.     

超高效液相色谱-串联质谱法对比11种净化方式对当归中50种农药残留检测的影响

采用超高效液相色谱-串联质谱仪(UPLC-MS/MS)同时测定当归药材中50种农药残留,对比了11种净化方式对检测结果的影响,筛选出最有效的基质净化方法。 以回收率为考察指标,评估了不同基质净化方法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,NaCl净化,在电喷雾正负离子扫描、依赖保留时间的动态多反应监测模式(dMRM)下,以基质匹配内标法定量。 结果表明,50种农药在NaCl净化法下回收率最高,在各自的浓度范围内线性关系良好(R²>0.99);3个添加水平(10、50、100 μg/kg)下,大多数农药的回收率为70.1%~117.7%,相对标准偏差(RSD,n=6)不大于 20.0%,50种农药的定量限为1.0~20.0 μg/kg。 该方法为当归中准确、高效、经济的检测目标物提供了可靠依据。     

气相色谱-串联质谱法测定茶叶中88种农药残留量

采用气相色谱-串联质谱(GC-MS/MS)分析技术,建立了高灵敏度检测茶叶中88种农药残留量的方法。目标化合物经加速溶剂萃取(ASE), Carb/NH2净化小柱净化,乙腈-甲苯(3:1, v/v)洗脱,采用GC-MS/MS测定。对方法的准确性、精密度、线性范围、最低检出限(LOD)和定量限(LOQ)进行了测试。其中87.5%的农药在低水平(6.4 μg/kg)的加标回收率为70%～100%; 87.5%的农药的相对标准偏差(RSD)小于15%。每个化合物均采用灵敏度最高的离子对进行定量,并采用空白茶叶基质配制标准工作液。LOQ以10倍信噪比(S/N=10)计算,86.4%农药的LOQ值低于10 μg/kg。该方法灵敏度高、准确、可靠,适用于绿茶、乌龙茶、红茶以及普洱茶中多种农药残留量的检测。     

Microwave assisted solvent extraction and coupled-column reversed-phase liquid chromatography with UV detection use of an analytical restricted-access-medium column for the efficient multi-residue analysis of acidic pesticides in soils.

A screening method has been developed for the determination of acidic pesticides in various types of soils. Methodology is based on the use of microwave assisted solvent extraction (MASE) for fast and efficient extraction of the analytes from the soils and coupled-column reversed-phase liquid chromatography (LC-LC) with UV detection at 228 nm for the instrumental analysis of uncleaned extracts. Four types of soils, including sand, clay and peat, with a range in organic matter content of 0.3-13% and ten acidic pesticides of different chemical families (bentazone, bromoxynil, metsulfuron-methyl, 2,4-D, MCPA, MCPP, 2,4-DP, 2,4,5-T, 2,4-DB and MCPB) were selected as matrices and analytes, respectively. The method developed included the selection of suitable MASE and LC-LC conditions. The latter consisted of the selection of a 5-microm GFF-II internal surface reversed-phase (ISRP, Pinkerton) analytical column (50 x 4.6 mm, I.D.) as the first column in the RAM-C18 configuration in combination with an optimised linear gradient elution including on-line cleanup of sample extracts and reconditioning of the columns. The method was validated with the analysis of freshly spiked samples and samples with aged residues (120 days). The four types of soils were spiked with the ten acidic pesticides at levels between 20 and 200 microg/kg. Weighted regression of the recovery data showed for most analyte-matrix combinations, including freshly spiked samples and aged residues, that the method provides overall recoveries between 60 and 90% with relative standard deviations of the intra-laboratory reproducibility's between 5 and 25%; LODs were obtained between 5 and 50 microg/kg. Evaluation of the data set with principal component analysis revealed that the parameters (i) increase of organic matter content of the soil samples and (ii) aged residues negatively effect the recovery of the analytes.     

大米中多种残留农药的固相萃取-气相色谱-质谱分析

建立了一种同时测定大米中有机氯、有机磷、氨基甲酸酯和拟除虫菊酯等4类农药残留量的分析方法。通过比较二氯甲烷、三氯甲烷、乙腈、乙酸乙酯和不同比例的己烷-丙酮混合溶剂等8种溶剂的提取效果,选择以二氯甲烷为提取溶剂;以Florisil固相萃取小柱净化,通过以不同比例的己烷-丙酮作洗脱溶剂,发现体积比为4∶1的己烷-丙酮的洗脱效果最佳,在选定的洗脱条件下,样品的净化效果良好;用气相色谱-质谱测定,以保留时间、选择离子及其相对丰度定性,以外标法定量。以低限加标样品的3倍信噪比确定方法的检出限(LODs),以两个添加水平测定样品的回收率和相对标准偏差(RSD)。该方法的检出限达到μg/kg水平;除敌敌畏、乐果、pp′-DDT等几种农药外,大多数农药的加标回收率在75%和120%之间,RSD均低于10.4%,r≥0.992。该方法简便、快速、灵敏,能够满足同时测定大米中多种类残留农药的要求,可以作为大米中农药多残留的例行分析和确证分析的方法。     

Multiresidue determination of pesticides by solid-phase extraction and GC-MS for control of peach production in Bulgaria

A multiresidue analytical method based on acetone extraction and clean-up/pre-concentration on polymeric sorbents was validated for 42 pesticides in peach matrix in order to control safety of fresh production on the Bulgarian market. Matrix-matched calibration was used by addition of pesticides just before SPE. In this way the standards and the samples undergo exactly the same procedure and an improvement of recoveries for the target analytes was observed. The identification and quantification were done by gas chromatographic technique with mass-spectrometric detection (GC-MS). The limits of detection obtained were 0.005?mg?kg^–1 or lower for the most of analytes, and the recovery data were in range 73–109% at three spiked levels 0.01, 0.1 and 0.2?mg?kg^?1. The validated method was used for monitoring of selected pesticides in fresh peach fruits home production. Approximately 30% of the analysed lots (total 33 samples) contained residues mainly of cypermethrin and procymidone, but did not exceed EU MRLs.     

Validation of short run time LC-ESI (+) MS/MS method for determination of twenty recommended pesticide residues in food based on QuEChERS extraction technique

Food is expected to contain pesticide residues that might have many problems due to their toxicities for human and animals. So, it is very important to detect and quantify the pesticides contamination levels to increase food safety for the human. The target of our study is to analyse a 20 new pesticides including different pesticide classes such as 1 acaricide, 3 fungicides, 2 plant growth regulators, 11 herbicides, 1 insecticide, 1 rodenticide, and 1 metabolite which were selected according to their modern application in the Egyptian agriculture as well as the recommendation of the Egyptian Agriculture Pesticides Committee (APC). The research is focused on the method validation for the routine analysis of the targeted pesticide residues according to the European SANTE/11,813/2017 guideline. The validation was carried out by fortifying of three levels at 0.01, 0.05 and 0.1 mg/kg in four blank matrices: apple, green beans, fennel seeds and rice which represent different classes of food. The most common citrate buffered QuEChERS extraction method and liquid chromatography coupled with triple quadrupole mass spectrometry (LC-MS/MS) device were used. The mass spectrometer was operated in the positive electrospray ionisation ESI (+) mode and the non-scheduled multiple reactions monitoring (MRM) method in a short run time of 16.0 min. The limits of quantifications (LOQs) for all pesticides ranged between 0.01 and 0.05 mg/kg. Good linearity of the method was in the concentration range 0.001–0.5 μg/ml with acceptable correlation coefficients (r²) ≥ 0.99 for all analytes. The average recoveries for all the target pesticide residues were in the range of 70–120% with relative standard deviations RSDs ≤ 20%. The matrix effect was compensated by using the standard addition method. This short run time LC ESI (+) MS/MS Method may help laboratories which deal with the routine pesticide residues analysis in different food samples.     

两种水产品中农药多残留分析的样品前处理方法及其在111种农药和相关化学品残留同时检测中的应用

建立了两种针对水产品中农药多残留分析的快速样品前处理方法,并将其应用于111种农药及相关化学品残留检测。在样品前处理方法Ⅰ中,样品经丙酮-乙酸乙酯-正己烷(体积比为1∶1∶1)混合溶剂提取,乙腈转溶;在样品前处理方法Ⅱ中,样品用乙腈-水溶液均质,超声波辅助提取,液-液分配。两种方法所得到的提取液分别用Envi-18柱和PSA柱净化后进行气相色谱-质谱(GC-MS)分析。采用选择离子扫描(SIM)方式,外标法定量。该方法简便、快速,在优化的样品前处理条件和GC-MS分析条件下,方法的检出限(S/N=3)为0.001～0.026 mg/kg;在加标水平为0.25 mg/kg时,采用方法Ⅰ时的回收率为72%～113%,相对标准偏差（RSDs）为3.4%～12.1%;采用方法Ⅱ时的回收率为51%～127%(其中回收率为70%～120%的占94%),RSDs为3.2%～13.8%。     

高效液相色谱法测定一次性卫生用纺织品中荧光增白剂

建立了同时测定一次性卫生用纺织产品中4种荧光增白剂(FWA 357、FWA 220、FWA 204和FWA 113)的高效液相色谱-二极管阵列检测器(HPLC-DAD)检测方法。样品用20 mL超纯水作提取剂,于80 ℃下振荡提取30 min,用高效液相色谱进行定性、定量分析。采用SB Phenyl色谱柱(250 mm×4.6 mm, 5 μm)分离,以5 mmol/L乙酸铵和乙腈为流动相梯度洗脱,成功地将待测荧光物质分离。4种荧光增白剂在0.025~400 mg/L范围内线性关系良好,线性相关系数(r²)均大于0.9999;检出限(S/N=3)分别为0.1、0.1、0.02、0.02 mg/L;方法定量限(S/N=10)分别为1.0、2.0、5.0、5.0 mg/kg。添加水平为20~800 mg/kg时,回收率为83.7%~101.0%,相对标准偏差(n=6)为2.4%~7.0%。该方法前处理简单,回收率高,适用于一次性卫生用纺织产品中4种荧光增白剂的测定。     

Multiresidue Analysis of Pesticides in Water from Rice Cultures by On-line Solid Phase Extraction Followed by LC-DAD

Abstract

An automated on-line solid phase extraction procedure followed by liquid chromatography with diode array detection was investigated for the determination of different classes of pesticides in water samples containing varied amount of humic substances. The different pesticides used were: carbendazin, carbofuran, atrazine, diuron, propanil, molinate, alachlor, parathion-ethyl, diazinon, trifluralin and the degradation products deisopropylatrazine and deethylatrazine. Humic substances extracted from a Brazilian sediment were used from 5 to 80 mg/l and their influence on recoveries was evaluated in neutral and acidic media. Recoveries higher than 70% were obtained for all the pesticides, from the preconcentration of 75 ml of aqueous sample fortified at 2 ng/ml using precolumns packed with PLRP-S. Good recoveries were obtained at neutral pH for most of the analytes up to 40 mg/l of humic acid. Only at 80 mg/l the recoveries were significantly affected, both at acidic and neutral pH. The method was applied to the determination of pesticides in river water spiked at 0.1 to 1 ng/ml. Detection limits obtained for water containing 10 mg/l of humic acid were between 0.05 and 0.3 ng/ml.     

低温冷冻及分散固相萃取净化-超高效液相色谱-串联质谱法测定植物油中104种农药残留

建立了适用于植物油中104种农药残留的检测方法。通过液液萃取(LLE)提取目标化合物,再借助离心、冷冻和分散固相萃取(D-SPE)净化手段,依托超高效液相色谱-串联质谱测定。以回收率和共提取物为衡量指标,着重优化了6种提取方式、不同冷冻时间及PSA(primary secondary amine)、GCB(graphite carbon black)和C18这3种不同固相萃取填料不同组合的效果。在0.01、0.02和0.05 mg/kg水平的平均添加回收率为55%~121%, RSD为0.47%~19.2%, 80%的目标物的定量限可达到1 μg/kg,低于我国相关标准限量,能够满足多种农药残留同时分析的要求。该方法步骤简便、可靠、稳定,可应用于进口植物油中多种农药残留的快速检测与确证的日常检测工作中,具有一定的推广价值。