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。     

气相色谱–电子捕获检测法测定食品中有机氯类和拟除虫菊酯类农药残留量

目的 建立不同食品基质中有机氯类和拟除虫菊酯类农药的通用前处理技术, 结合气相色谱–电子捕获检测器(gas chromatography–electron capture detector, GC-ECD), 实现有机氯类和拟除虫菊酯类农药的快速定量分析。方法 本研究选择15种有机氯类和拟除虫菊酯类农药作为对象, 采用乙腈提取, 无水硫酸钠干燥, Forisil固相萃取、结合浓硫酸磺化净化技术, 通过GC-ECD检测, 完成样品中有机氯类和拟除虫菊酯类药物的同时快速测定。结果 此方法最低检出限和定量限分别达0.25 μg/kg和0.50 μg/kg, 同时选用3个不同浓度的加标实验, 回收率在70.0%~100%之间, 相对标准偏差皆小于10%。结论 本方法操作简便、高效、灵敏度高, 易于普及, 适用于不同食品基质中有机氯类和菊酯类药物的同时检测。     

加速溶剂萃取-气相色谱测定茶叶中多种农药残留

目的建立一种加速溶剂萃取(ASE)-气相色谱(GC)同时测定茶叶中三氯杀螨醇(有机氯类)与多种除虫菊酯类农药残留的新方法。方法样品用环己烷∶乙酸乙酯(1∶1,V/V)提取,提取液经florisil固相萃取柱净化后,采用气相色谱-电子捕获检测器(GC-ECD)进行检测。结果各农药在0.01、0.05、0.25mg/kg3个添加水平上的平均回收率都在90%以上,RSD在0.3%～3.8%之间。结论该方法快速、溶剂用量少、重现性好,能够满足茶叶中有机氯与拟除虫菊酯类农药残留的检测要求。     

海藻中有机氯和拟除虫菊酯类农药残留分析

目的 检测海藻中有机氯和拟除虫菊酯类农药的残留情况,并对农药污染现状进行分析与评价.方法 羊栖菜、昆布、紫菜和石花菜样品分别用石油醚、正己烷:丙酮(1:1)、丙酮:二氯甲烷(1:1)、丙酮:二氯甲烷(1:1)溶液进行微波辅助萃取,采用超声波萃取联合气相色谱(GC),测定有机氯和拟除虫菊酯类农药含量.结果 六氯苯、七氯、...     

牛奶中有机氯农药及拟除虫菊酯农药多残留的HS-SPME-GC-MS分析方法研究

目的 建立牛奶中有机氯农药和拟除虫菊酯类农药的快速多残留测定方法.方法 以顶空固相微萃取作为前处理手段,采用气相色谱-质谱联用方法测定牛奶样品中31种农药组分（其中有机氯农药23种,拟除虫菊酯类农药8种）,并以13C6-六氯苯和13C10-灭蚁灵作为稳定的同位素内标物,采用内标法定量.结果 方法的最低检测限在0.002～0.2μg/L之间,回收率在85%～110%之间.相对标准差在3%～12%之间.结论 该方法快速、简单、准确、可靠、环保.适用于批量牛奶样品中农药残留的筛查.     

固相萃取-气相色谱法检测金银花中9 种拟除虫菊酯农药残留

采用固相萃取净化,气相色谱电子捕获检测器检测,建立了金银花中9 种拟除虫菊酯农药残留量的检测方法。金银花样品经正己烷涡旋振荡提取、TPH固相萃取柱净化后,用气相色谱检测。9 种拟除虫菊酯农药的线性范围在0.01～0.8 mg/L,平均回收率为82.8%～104.6%,相对标准偏差为3.5%～5.7%,检出限为0.002～0.005 mg/L。该方法灵敏、准确,适用于金银花中9 种拟除虫菊酯类农药残留量分析。     

分散固相萃取-气相色谱法快速测定食用植物油中66种农药残留

建立分散固相萃取法结合气相色谱技术同时快速测定食用植物油中有机磷、有机氯和拟除虫菊酯66种农药残留的方法。样品经乙腈溶剂3次提取后,使用PSA(Primary secondary Amine,N-丙基乙二胺)和C18分散固相萃取净化,提取溶液经氮吹浓缩过滤后一部分注入气相色谱-电子捕获检测器检测,另一部分经气相色谱-火焰光度检测器检测。样品在0.08、0.16和0.40 mg/kg添加水平的回收率试验中,平均回收率为62.3%~112.3%,相对标准偏差不大于8.6%,检出限在0.001~0.018 mg/kg之间,基本满足国内外对食用植物油中农药最低残留限量的标准要求。     

微波辅助萃取-气相色谱法测定茶叶中多种有机氯和拟除虫菊酯农药残留

建立了茶叶中18种有机氯和9种拟除虫菊酯农药残留微波辅助萃取．气相色谱分析方法。运用正交设计法对微波萃取条件进行了优化,茶叶样品用正己烷-二氯甲烷混合溶N（1：2,V／V）进行萃取,萃取液用弗罗里硅土和中性氧化铝混合层析柱净化,采用J＆WDB-1701毛细管柱分离,GC．ECD法同时测定。在0．4、0．2、0．1ml（0．5μg／m1有机氯农药＋1．0μg／ml拟除虫菊酯农药）三个水平添加时的平均回收率（n=5）分别为80．9％～118．5％、88．4％～120．7％、80．9％～116．3％;相对标准偏差分别为2．09％～6．70％、1．89％～6．49％、1．98％～11．87％。该方法的检出限为：有机氯农药0．0004～0．0048mg／kg,拟除虫菊酯农药0．0033～0．0400mg／kg。     

固相萃取结合气相色谱法测定茶叶中三氯杀螨醇和拟除虫菊酯类农药残留

目的建立茶叶中三氯杀螨醇和7种拟除虫菊酯类农药的检测方法。方法以丙酮作为提取溶剂,提取液经石墨碳黑/氨基(Carbon/NH2)固相萃取小柱净化后,用DB-5毛细管柱分离,采用气相色谱-电子捕获检测器(GC-ECD)进行测定。结果三氯杀螨醇和拟除虫菊酯类农药在20～800μg/L范围内线性良好,相关系数(r)均在0.998以上,最低检出限为0.23～1.38μg/kg,样品的加标回收率在88.5%～106.4%之间,相对标准偏差(RSD)在2.5%～10.7%之间。结论本方法净化效果好、灵敏度高、重现性好,可用于茶叶样品中三氯杀螨醇和拟除虫菊酯类农药残留量的检测。     

超声波辅助提取-GC/MS法测定蔬菜中18种农药

开展待测农药残留样品的高效、快速检测方法研究,建立快速、准确测定蔬菜中有机氯、拟除虫菊酯农药的超声波辅助-气相色谱-质谱检测方法。用气相色谱-质谱检测方法,乙腈作为提取溶剂,超声波辅助提取,CARB/NH_2固相萃取小柱净化,通过Rtx-5MS色谱柱分离检测,用外标法对蔬菜10种有机氯和8种拟除虫菊酯类农药残留进行了测定。方法灵敏准确、简便快捷,满足现阶段蔬菜中的农药残留分析要求。     

动态微波辅助萃取法快速萃取苹果中8种 氨基甲酸酯类农药

目的 建立一种绿色的动态微波辅助快速萃取法结合高效液相色谱-串联质谱法测定苹果中八种氨基甲酸酯类农药的方法。方法 首先,以水为萃取溶剂,利用动态微波辅助萃取法对苹果中氨基甲酸酯类农药进行快速萃取;之后通过两步固相萃取法对所获得的萃取物进行净化和富集;最后,采用高效液相色谱-串联质谱法对目标化合物进行分析。结果 实验中对影响动态微波辅助萃取和固相萃取效率的实验条件进行了优化,最优的实验条件为：萃取剂为纯水,微波萃取功率为600 W;微波萃取时间为10 min;萃取剂流速为1.0 mL min-1;固相萃取洗脱剂为2 mL的乙醇。八种氨基甲酸酯类农药在8~800 ng g-1范围内成线性关系,相关系数为0.994~0.999;检出限为1.1~4.2 ng g-1;方法的加标(8 ng g-1)回收率为71%~90%。结论 该方法可以用于苹果中氨基甲酸酯类农药的快速检测。     

固相萃取-液相色谱法测定水果中的氨基甲酸酯与有机磷农药

建立了固相萃取-高效液相色谱同时测定水果中4种氨基甲酸酯与一种有机磷的方法.对提取溶剂、固相萃取柱种类、洗脱剂类型和用量及检测的色谱条件进行筛选和优化.样品经乙腈超声提取,弗罗里硅土固相萃取柱净化,净化后的样品采用液相色谱柱分离,以甲醇:水(体积比70∶ 30)为流动相,紫外检测波长为210nm,流速1.0mL/min...     

浊点萃取-气相色谱-质谱法测定苹果汁中的有机磷农药残留

本文对苹果汁中45种有机磷类农药的提取、净化技术和气相色谱质谱检测条件进行了研究。以苹果汁为基质材料,45种有机磷类农药在1、5、10μg/L三个水平上对苹果汁进行添加回收率实验。结果表明:45种有机磷类目标物在优化条件下的回收率为71.16%~117.94%,相对标准偏差1.20%~15.13%(n=5),方法检出限为0.01~0.22μg/L。45种有机磷类农药能够实现很好的分离,线性范围在10~2000μg/L,线性相关系数大于0.984。本方法操作简单,结果准确,由于几乎不使用有机溶剂也减少了分析过程对环境和人体的危害。      

SPE-GC/MS测定苹果梨中19种有机氯农药残留

采用固相萃取技术结合气相色谱—质谱（SPE-GC/MS）技术建立了同时检测苹果梨中19种农药残留的分析方法,并对样品预处理过程中萃取剂、萃取剂用量、取样量、固相萃取柱、洗脱剂等条件进行优化,采用选择离子监测（SIM）模式,外标法定量。结果表明,19种农药在线性范围内线性关系良好（R²≥0.996 7）;3个添加水平（20,40,200 μg/kg）的回收率为86.1%～108.9%,相对标准偏差＜10%;19种农药检出限为3.0～6.0 μg/kg,定量限为10.0～20.0 μg/kg;该方法样品前处理简单、准确性好、灵敏度高,适用于苹果梨中19种农药残留的筛选与测定。     

微波辅助水蒸气萃取结合液液分散微萃取法萃取西红柿中三嗪类农药残留

目的 建立一种基于微波辅助水蒸气萃取结合液液分散微萃取用于西红柿中三嗪类农药残留的绿色萃取方法。方法 西红柿样品经微波辅助水蒸气萃取后,用液液微萃取法对萃取液进行净化和富集。之后采用液相色谱-串联质谱法对三嗪类农药进行定性和定量分析。结果 微波辅助水蒸气萃取结合液液微萃取的最佳萃取条件为：微波功率为200W,萃取剂为水蒸气并添加300μL乙腈,样品与石英砂比例为1:2,收集液体积为18mL;分散液液微萃取中的萃取剂为350μL的氯仿,分散剂为600μL的丙酮,并加入0.2gNaCl以增加三嗪类农药的回收率。在最佳的萃取条件下,6种三嗪类农药在1、50和500 μg/kg添加水平的回收率为62.1%~108.1%;日内和日间精密度分别在1.6% - 6.7%和4.8%- 10.3%之间(n=6), 方法定量限为2 μg/kg。结论 该方法快速、准确、灵敏, 适合测定西红柿中三嗪类农药残留。     

固相萃取-气质联用法测定苹果中甲胺磷、地虫磷、甲基对硫磷和对硫磷的残留量

目的建立一种经固相萃取,以气相色谱-质谱法(gas chromatography-mass spectrometer,GC-MS)测定苹果中甲胺磷、地虫磷、甲基对硫磷和对硫磷残留量的方法。方法采用乙腈提取,石墨化碳/氨基复合固相萃取柱对苹果中的甲胺磷、地虫磷、甲基对硫磷和对硫磷进行净化,氮吹浓缩后利用气质联用仪测定其农药残留量。结果 4种有机磷农残在20~200μg/L线性范围内关系良好,相关系数(r~2)均大于0.995,检出限和定量限分别为1.4~3.5μg/kg和5.1~9.8μg/kg,当添加浓度为10~50μg/kg,回收率为81.2%~112.5%,测量结果RSD(n=5)在5.3%~13.7%之间。结论本法干扰低、快速高效,适合苹果中的甲胺磷、地虫磷、甲基对硫磷和对硫磷的残留量的测定。     

Determination of seven pyrethroid pesticide residues in vegetables by gas chromatography using carboxylated multi-walled carbon nanotubes as dispersion solid phase extraction sorbent

ABSTRACT

A novel carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) dispersive solid phase extraction (d-SPE) method combined with gas chromatography (GC) with an electron capture detector (ECD) was developed for the determination of seven pyrethroid pesticides in cucumber, spinach, eggplant, tomato and carrot. We optimised d-SPE conditions including the type and volume of the extractant, the type and amount of the sorbent, and shaking time. Under the optimal conditions, the linear range was from 2.0 to 2000 μg kg^?1. The recoveries were from 88.5% to 108.2%, with the corresponding RSDs <6%, correlation coefficients 0.9987–0.9998, LOD 0.5–2.9 μg kg^?1 and LOQ 1.5–9.7 μg kg^?1. The proposed method is simple, fast, and safe, with high recovery and sensitivity, and is applicable to analysis of pyrethroid pesticides in vegetable samples.     

A validated matrix solid-phase dispersion method for the extraction of organophosphorus pesticides from bovine samples

A method based on matrix solid-phase dispersion (MSPD) was developed for the quantitative extraction of five organophosphorus (OPPs) pesticides from bovine samples. The determination was carried out by high performance liquid chromatography (HPLC) with diode array spectrophotometric UV detection. The MSPD extraction with octadecylsilyl (C18) sorbent combined with a silica gel clean-up and acetonitrile elution was optimised for chlorpyrifos, chlorfenvinphos, diazinon, fenitrothion, and parathion-methyl. The method was validated, yielding recovery values higher than 94%, except for chlorfenvinphos in liver (55%), and precision values, expressed as relative standard deviations (RSDs), which were less than or equal to 15% in liver and 11.5% in muscle at spiking levels of 0.25, 2.5 and 5 μg g⁻¹. Linearity was studied from 0.5 to 15 μg g⁻¹, and the limits of detection (LODs) were found to be lower than 0.1 μg g⁻¹_. This method was applied to the analysis of real samples with confirmative analyses performed using gas chromatography–mass spectrometry (GC–MS) in selected ion monitoring mode (SIM).     

Micro-solid-phase extraction (µ-SPE) of organophosphorous pesticides from wheat followed by LC-MS/MS determination

A rapid, selective and effective method of extraction, clean-up and concentration of organophosphorous pesticides from wheat followed by electrospray (ESI) LC-MS/MS analysis was developed. The μ-SPE (micro-solid-phase extraction) procedure resulted in good analytical performance and reduced at the same time matrix effects, analysis time and solvent consumption. Limits of detection (LODs) and quantification (LOQs) were in the range of 0.3–10 and 1–30 μg kg^?1, respectively, with good reproducibility (RSD ≤ 13.8) and recoveries between 75% and 109%. Coefficients of determination (r²) were greater than 0.996 for the studied pesticides. Despite the reduced sorbent bed mass of μ-SPE tips (4.2 mg), the analytical data showed that no saturation phenomena occurs in the tested range of concentration both for single compounds and mixtures. Several real samples were analysed and the concentrations of the selected pesticides were found to be below the respective maximum residue limit (MRLs).     

Graphene as dispersive solidphase extraction materials for pesticides LC-MS/MS multi-residue analysis in leek,onion and garlic

A multi-residue analytical method was validated for 24 representative pesticides residues in onion, garlic and leek. The method is based on modified QuEChERS sample preparation with a mixture of graphene, primary secondary amine (PSA), and graphitised carbon black (GCB) as reversed-dispersive solid-phase extraction (r-DSPE) material and LC-MS/MS. Graphene was first used as an r-DSPE clean-up sorbent in onion, garlic and leek. The results first show that the mixed sorbent of graphene, PSA and GCB has a remarkable ability to clean-up interfering substances in the r-DSPE procedure when compared with the mixture of PSA and GCB. Use of matrix-matched standards provided acceptable results for tested pesticides with overall average recoveries between 70.1% and 109.7% and consistent RSDs <15.6%. In any case, this method still meets the 1–10 μg kg^–1 detection limit needed for pesticide testing and may be used for qualitative screening applications in which any identified pesticides can be quantified and confirmed by a more intensive method that achieves >70% recovery.