微柱固相萃取结合气相色谱-质谱法分析茶叶中有机氯农药

研制了碳纳米管微柱,建立了测定有机氯类农药的微柱固相萃取气相色谱-质谱法。样品泵入多壁碳纳米管微柱,8种有机氯类农药吸附保留到微柱,引入甲醇洗脱,气质联用选择离子监测方式检测洗脱液中有机氯类农药。考察了影响微柱固相萃取有机氯类农药的各种因素,包括样品流速、样品体积、洗脱剂种类、洗脱剂体积和碳纳米用量等。建立的方法适用于茶叶水提液中8种有机氯类农药分析,检出限0.015～0.25μg/kg。加标样品回收率74.5%～107.2%,相对标准偏差小于12%。     

QuEChERS-气相色谱-质谱法检测洋葱中20种农药残留

目的建立洋葱中20种农药残留的气相色谱-质谱(gas chromatography-mass spectrometry, GC-MS)分析方法。方法样品前处理采用QuEChERS方法,用乙腈溶液进行提取,经N-丙基乙二胺(primary secondary amine, PSA)、十八烷基硅烷键合硅胶(C_(18))和无水硫酸镁固相分散净化,浓缩定容后用GC-MS在选择离子监测模式(select ion monitoring, SIM)下进行测定,外标法定量。结果 20种农药在0.1～0.5μg/mL范围内线性关系良好,相关系数均大于0.99。方法检出限为0.0003～0.0222 mg/kg,方法定量限为0.0009～0.0741 mg/kg,加标回收率为87.9%～110.0%,相对标准偏差(relative standard deviation, RSD)为0.4%～3.8%。结论该方法前处理过程简单、快速,灵敏度高,重现性好,适用于洋葱中20种农药残留的测定。     

Sample preparation method for the analysis of some organophosphorus pesticides residues in tomato by ultrasound-assisted solvent extraction followed by dispersive liquid–liquid microextraction

A very simple and economic method for organophosphorus pesticides (OPPs) residues analysis in tomato by means of gas chromatography–flame photometric detection (GC–FPD) has been developed. The method involves a rapid and small-scale extraction. The sample was homogenised and extraction of the OPPs with acetone was carried out assisted by sonication. No clean-up or evaporation were required after extraction. Pre-concentration of the OPPs from the acetone extract was done by using dispersive liquid–liquid microextraction (DLLME) technique. Chlorobenzene was added in micro-level volume as extraction solvent and triphenylphosphate as internal standard in DLLME procedure. The method showed good linearity over the range assayed (0.5–1000 μg kg⁻¹) and the detection limits for the pesticides studied varied from 0.1 to 0.5 μg kg⁻¹. Repeatability studies resulted a relative standard deviation lower than 10% in all cases. The proposed method was used to determine pesticides levels in tomatoes grown in open field.     

气相色谱-质谱法测定食用植物油中氯丙醇酯的含量方法验证研究

目的建立一种同时测定食用植物油中3-氯-1,2-丙二醇脂肪酸酯(3-MCPD酯)、2-氯-1,3-丙二醇脂肪酸酯(2-MCPD酯)、1,3-二氯-2-丙醇脂肪酸酯(1,3-DCP酯)和2,3-二氯-1-丙醇脂肪酸酯(2,3-DCP酯)含量的气相色谱-质谱(GC-MS)方法。方法植物油样品经叔丁基甲基醚-乙酸乙酯溶液(8∶2,V/V)溶解,在甲醇钠-甲醇溶液中发生酯键断裂反应,用冰乙酸中和正己烷去脂,经硅藻土小柱净化,七氟丁酰基咪唑(HFBI)衍生,以GC-MS法测定,采用同位素内标进行定量。结果经5家检验机构验证,4种氯丙醇酯(以对应的氯丙醇计)在0.02~0.4 mg/L范围内线性良好,相关系数r~2均大于0.999,在0.2~2.0 mg/kg水平的加标回收率在78.5%~109.8%之间,RSD为2.2%~18.8%,检出限均为0.1 mg/kg。结论 2014年英国FAPAS分析实验室能力验证和5家机构协同验证的结果证实,该方法线性良好,准确度、精密度高,检测成本较低,适用于食用植物油中氯丙醇酯的检测。     

气相色谱-质谱法测定白酒中塑化剂残留前处理方法的优化

目的对气相色谱-质谱法(gas chromatography-mass spectrometer,GC-MS)检测白酒中17种塑化剂的前处理方法进行优化。方法对试样中乙醇含量、总酸、总酯及盐添加量4个方面的变化进行了考察。用正己烷提取,离心后取上清液进行分析,根据回收结果筛选出最优的处理参数,并通过对质控样的测定以验证其实际的检测效果。结果当试样中的乙醇含量为10%(V/V)、盐添加量为0.3 g/mL时,17种塑化剂的回收结果较为理想;总酸含量在0～2.0 g/L及总酯含量在0～4.0 g/L范围内,其浓度的变化对测定结果无显著影响。在0.10～1.00μg/mL的浓度范围内,17种塑化剂的检测响应值均具有良好的线性关系,相关系数均大于0.99;方法的检出限范围为0.02～0.06 mg/kg(n=10),定量限范围为0.05～0.19 mg/kg(n=10);当在空白样品中的加标量为0.10、0.50、1.00 mg/kg时,17种塑化剂的平均回收率为80.0%～120.0%,相对标准偏差为2.47%～6.97%(n=6);采用本方法对含有14种塑化剂的质控样进行测定,所有测定结果与指定值间的相对偏差均小于10%,满足实际应用的精密度要求。结论经前处理后的方法,具有操作简易,回收率高,精密度好,检测结果准确等优点,可满足日常监督中对白酒塑化剂检测的需求。     

固相萃取-气相色谱/质谱法同时测定植物油中胆固醇和维生素E

建立了固相萃取（SPE）净化结合气相色谱-质谱联用（GC-MS）同时检测植物油中胆固醇和维生素E四种异构体（α-生育酚、β-生育酚、γ-生育酚和δ-生育酚）的分析方法。样品采用氨基固相萃取小柱提取净化,洗脱液经DB-5MS色谱柱分离,GC-MS选择离子监测模式（SIM）测定。实验表明,胆固醇和维生素E四种异构体在各自浓度范围内线性关系良好。方法的回收率为83.9%～108.0%,相对标准偏差（RSD）为1.3%～9.3%,胆固醇和α-生育酚、β-生育酚、γ-生育酚和δ-生育酚的检出限分别为0.2 mg/kg、1.0 mg/kg、2.0 mg/kg、2.0 mg/kg、0.8 mg/kg。结果表明,该方法结果可靠,可用于日常检测。     

竹笋壳提取物中有效成分的GC/MS分析研究

为了探讨竹笋壳中生物活性物质的组成成分,利用超声波辅助-有机溶剂提取法提取竹笋壳中的活性物质,并经大孔吸附树脂初步分离纯化。以N,O-双(三甲基硅烷)三氟乙酰胺(BSTFA,含1%的三甲基氯硅烷TMCS)为衍生化试剂,采用气相色谱-质谱联用技术及运用面积归一化法定性定量鉴定竹笋壳提取物中所含有效成分。结合气相色谱-质谱标准谱图库NIST进行人工结构解析确定了15种物质的化学结构,其中常见脂肪酸有11种,酚酸有2种,脂肪酸的相对含量为29.71%,酚酸的相对含量为10.96%。     

气相色谱测定植物油中反式脂肪酸方法的探讨

通过对GB/T 22110—2008色谱运行条件进行调整,将柱温初始温度由60℃调高至115℃,保留时间由5 min缩短至1 min;阶段1升温速率由5℃/min加快至10℃/min;增加1个阶段,即采取10℃/min的升温速率由165℃升高至185℃;并将最后1个阶段运行时间由17 min缩短为5min。通过缩短各组分间空白运行时间后,色谱运行时间由74 min缩短为35 min,图谱的分离度、基线、峰形都较好。重复性符合GB/T 22110—2008中"同一样品平行测定结果之差不得超过算数平均值的10%"的要求。时间缩短后,极大地提高了检测效率。     

固相萃取-气相色谱法同时检测草莓中13种 农药残留

目的 建立一种固相萃取-毛细管柱气相色谱方法,可以同时检测草莓中13种农药残留量。方法 草莓样品匀浆后,经乙腈提取,NH₂固相萃取柱净化,采用HP-5毛细管气相色谱柱进行分离,GC-ECD 进行定性及定量分析。结果 13 种农药残留的色谱图分离效果良好,线性相关系数均大于0.996,方法检出限在0.01 mg.kg_-1~0.5 mg.kg_-1之间。添加回收试验表明,该方法平均回收率在70.5~114.5 % 之间,相对标准偏差在2.17~6.85 %之间。结论 该方法简单、快速、灵敏、净化效果好、回收率高,适合草莓中多种农药残留的检测和安全监控。通过对50份草莓样品进行检测,检出百菌清、乙草胺、毒死蜱、粉唑醇、醚菌酯、烯酰吗啉6种农药。     

气相色谱-质谱法测定食用植物油中3-氯丙醇酯的不确定评估

目的评估气相色谱-质谱法面积比法测定食用植物油中3-氯丙醇酯的不确定度。方法根据JJF1059.1-2012《测量不确定度的评定和表示》,不确定度的主要来源为标准品、检测仪器和样品等参数,同时对各不确定度分量进行合成和扩展。结果当取样量为0.0100 g,k=2(95%置信度),测得的食用植物油中3-氯丙醇酯含量为(6.04?0.10)mg/kg。结论本方法可为评定食用植物油中3-MCPD酯含量的测量结果和方法的可靠性提供科学依据。     

气相色谱-质谱法测定葡萄中苯醚甲环唑的不确定度评定

目的：评定气相色谱-质谱法测定葡萄中苯醚甲环唑时的不确定度。方法：根据GB 23200.8—2016 《食品安全国家标准 水果和蔬菜中500种农药及相关化学品残留量的测定 气相色谱-质谱法》建立模型,根据JJF 1059.1—2012《测量不确定评定和表示》对不确定度来源进行分析量化。结果：本方法测定苯醚甲环唑的合成不确定度为2.258%,扩展不确定度为0.0451,葡萄中苯醚甲环唑测定结果为（0.06047±0.00273）mg/kg,k=2。结论：本方法不确定度主要来源为标准溶液配制及其曲线拟合,重复性测定对实验结果准确性影响较小。     

Development of a fast multiresidue method for the determination of pesticides in dry samples (wheat grains,flour and bran) using QuEChERS based method and GC–MS

In this study a multiresidue method for the determination of 24 pesticides in wheat, white flour and bran using gas chromatography coupled to mass spectrometry with negative chemical ionisation and selected ion monitoring (GC–MS (NCI–SIM)) was developed and validated. The QuEChERS method was used for the extraction of different pesticides. The method was validated evaluating the following parameters: linearity, limit of detention, limit of quantification, matrix effect as well as precision and accuracy, evaluating the percentage of recovery at four different spike levels. The linear range used in the calibration curves was from 1.0 to 100 μg L⁻¹ for wheat and 2.0 to 200 μg L⁻¹ for flour and bran, both with values of r² > 0.99. The recoveries had been considered satisfactory presenting values between 70% and 120% with RSD < 20% for the majority of compounds.     

Multiresidue method for the determination of 77 pesticides in wine using QuEChERS sample preparation and gas chromatography with mass spectrometry

A method based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) sample preparation method and gas chromatography with mass spectrometric detection by selected ion monitoring (GC/MS-SIM) was developed for simultaneous determination of 77 pesticide residues in wine. An extraction of 10 ml of sample with acetonitrile followed by liquid–liquid partition formed by the addition of 4 g MgSO₄ and 3 g NaCl was applied in the sample preparation. The clean-up was carried out by applying dispersive solid-phase with 150 mg MgSO₄ as well as 50 mg primary secondary amine (PSA). One quantitation ion and at least two identification ions were selected in the analytical method for each pesticide compound by GC/MS. The recovery data were obtained by spiking blank samples at two concentration levels (0.05 and 0.2 mg l^?1). The recoveries of all pesticides were in the range 70–110%, with intra-day precision of less than 15%, and the inter-day precision of less than 22% and 15% for 0.05 and 0.2 mg l^?1 fortification levels, respectively. Linearity was between 0.02 and 2 mg l^?1 with determination coefficients (R ²) greater than 0.98 for all compounds. The limits of quantification (LOQs) for the 77 pesticides ranged from 0.003 to 0.05 mg l^?1. This method was applied for routine analysis in market products.     

优化气相色谱-质谱法测定水果和蔬菜中五氯硝基苯残留量的前处理方法

目的建立检测水果和蔬菜中五氯硝基苯残留量的气相色谱-质谱联用方法。方法样品采用3种不同前处理法进行提取净化后,采用内标法进行定量。优化样品预处理方法,选择适宜的提取溶剂、最佳的超声和振荡时间,采用选择性离子扫描模式进行质谱检测。结论在0.02~0.10μg/m L添加水平,经正己烷提取和Qu ECh ERS柱净化处理的样品,其五氯硝基苯的平均回收率在68.32%~96.82%之间,相对标准偏差为3.4%~5.9%(n=6)。以信噪比S/N=3计算五氯硝基苯的最低检出限为0.002 mg/kg,方法的定量限为0.0067 mg/kg(S/N=10)。结论优化后的前处理方法结果准确、重现性好,检出限相对较低,满足水果和蔬菜中五氯硝基苯残留量的检测要求。     

橄榄油中农药多残留前处理方法研究及其应用于气相色谱、气质联用测定效果评估

建立了串联双柱净化前处理方法用于橄榄油中313种农药多残留的测定。橄榄油样品采用正己烷溶解,正己烷-乙腈-盐水三相分配除去部分杂质,农药组分转移至乙腈中,经串联双柱净化后供气相色谱仪(GC)和气相色谱-质谱仪(GC-MS)分析。气相色谱法采用火焰光度检测器(FPD)和电子捕获检测器(ECD)测试,外标法定量,适用于有机磷、有机氯和拟除虫菊酯等部分农药的测定。气相色谱-质谱法采用选择离子监测方式(SIM),外标法定量,适用于本法中所有313项农药的测定。在优化后的条件下进行分析,气相色谱-质谱法的检出限(S/N≥3)为0.01～0.03 mg/kg,在加标水平为0.01、0.05、0.20 mg/kg时,平均回收率为57.5%～148.4%(百菌清为44.3%),其中回收率在70%～120%之间的占93.9%,相对标准偏差为2.1%～17.8%。方法准确、灵敏、快速,可满足橄榄油中多种农药残留的风险监控需求并可扩展到其他植物油检测。     

Assessment of DFG-S19 method for the determination of common endocrine disruptor pesticides in wine samples with an estimation of the uncertainty of the analytical results

A gas chromatographic method for the determination of endocrine disruptor pesticides (Chlorpyrifos, Penconazole, Procymidone, Iprodione, Bromopropylate and Lambda-Cyhalothrin) in wine samples is described. A general DFG-S19 method for residual pesticide determination in all kind of food stuff was investigated to simplify and adopt for wine samples in this work. Alternative sample preparation routes were elucidated and compared according to their recovery values. Four different separation techniques were tested and the method employing florosil column after a LLE procedure was applied for wine samples with satisfactory recovery ratios (72–97%). The pesticides were extracted from the sample by cyclohexane–ethyl acetate mixture (1:1 v/v) and cleaned up by florosil column. The regression coefficients were at least 0.99 and relative standard deviations were no higher than 16%. Detection limits were in the range of 0.6–2.9 ng/mL and the relative expanded measurement uncertainties were calculated in the 7–22% range.     

Multi-residue method for the determination of 450 pesticide residues in honey, fruit juice and wine by double-cartridge solid-phase extraction/gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry

A multi-residue method was developed for the determination of 450 pesticide residues in honey, fruit juice and wine using double-cartridge solid-phase extraction (SPE), gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS-MS). The method development was based on an appraisal of the characteristics of GC-MS and LC-MS-MS for 654 pesticides as well as the efficiency of extraction and purification from honey, fruit juice and wine. Samples were first diluted with water plus acetone, then extracted with portions of dichloromethane. The extracts were concentrated and cleaned up with graphitized carbon black and aminopropyl cartridges stacked in tandem. Pesticides were eluted with acetonitrile + toluene, and the eluates were concentrated. For 383 pesticides, the eluate was extracted with hexane twice and internal standard solution was added prior to GC-MS determination. For 67 pesticides, extraction was with methanol prior to LC-MS-MS determination. The limit of detection for the method was between 1.0 and 300 ng g^-1 depending on each pesticide analyte. At the three fortification levels of 2.0-3000 ng g^-1, the average recovery rates were between 59 and 123%, among which 413 pesticides (92% of the 450) had recovery rates of 70-120% and 35 pesticides (8% of the 450) had recovery rates of 59-70%. There were 437 pesticides (97% of the 450) with a relative standard deviation below 25%; there were 13 varieties (3% of the 450) between 25.0 and 30.4%.     

食用植物油中残留溶剂测定的相平衡条件探讨

在采用非极性色谱柱对溶剂组分进行分离的基础上,对食用植物油残留溶剂顶空分析的相平衡条件进行研究.静态顶空分析的灵敏度主要取决于由平衡温度、平衡时间、气液相体积比所决定的气相提取效率,平衡温度显著影响分析的灵敏度,而平衡时间和气液相比例的选择性则不及平衡温度明显,提高平衡温度至溶剂沸点以上可以明显提高检测的灵敏度;通过实验得到优化的相平衡参数为:平衡温度为90℃、平衡时间为30 min、取样质量与汽化瓶体积的比值为1.0:2.5.     

A multiresidue method for the determination of 107 pesticides in cabbage and radish using QuEChERS sample preparation method and gas chromatography mass spectrometry

A rapid, specific and sensitive multiresidue method based on the modified Quick Easy Cheap Effective Rugged and Safe (QuEChERS) sample preparation method and gas chromatography with the electron impact mass spectrometric detection in the selected ion monitoring mode (GC–MS-SIM) using one target and two qualifier ions for the routine analysis of 107 pesticides in cabbage and radish has been developed. The recoveries for all the pesticides studied were from 80% to 115% with relative standard deviation lower than 15% in the concentration range of 0.030–0.360 mg/kg. The limit of quantitation (LOQ) for most compounds met MRLs for pesticides in cabbage and radish in Korea. This method was successfully applied to analysis commercial cabbage and radish samples.     

气相色谱质谱法快速测定谷物中敌草快含量的优化及其不确定度评定

目的优化气相色谱质谱法快速测定谷物中敌草快的分析方法,幵评定测定小麦敌草快含量的不确定度。方法样品经二氯甲烷净化,超纯水萃取,硼氢化钠溶液衍生,正己烷萃取上机,气相色谱质谱法测定,外标法定量。以大米、小麦、玉米为样品,测定加标回收率证实方法的可行性。以测定小麦敌草快数据为基础,依据JJF1135-2005《化学分析测量不确定度评定》和JJF1059.1-2012《测量不确定度评定与表示》,考察标准溶液配制、标准曲线拟合、样品称量、定容体积、仪器重复测量和回收率等主要因素引入的不确定度,幵对不确定度的各分量进行计算和合成。结果 3种谷物加标回收实验,均满足实验要求。当小麦中敌草快含量为0.094mg/kg时,在95%的置信区间下,其扩展不确定度为0.013mg/kg(k=2)。实验过程中的不确定度主要来源于标准溶液配制、标准曲线拟合。结论此法提高固液萃取、液液萃取效率,且操作简单。幵可通过选择精度高的移液、定容器皿,规范操作有效减少不确定度,保证测量结果的准确性。