固相萃取-气相色谱法检测茶叶中的有机磷农药残留量

建立了茶叶中22种有机磷农药的残留量的气相色谱分析方法. 样品用V(乙腈)∶V(丙酮)＝4∶1提取, 经Envi-Carb固相小柱净化, 以V(乙腈)∶V(甲苯)＝3∶1洗脱, GC-FPD检测, 外标法定量. 在添加0.05～1.0 mg/kg的水平, 22种有机磷的平均回收率在81.3%～107.9%之间, 相对标准偏差在1.1%～8.9%, 该方法的检出限为0.01～0.04 mg/kg. 该方法的灵敏度、准确度和精密度均符合农药残留量测定的技术要求.     

固相萃取-气相色谱法测定茶叶中多种有机磷农药

建立了固相萃取-气相色谱法同时测定茶叶中16种有机磷农药残留的方法.样品用丙酮超声提取后,经自制的N-丙基乙二胺(PSA)/活性炭固相萃取柱净化,以混合溶剂乙腈/甲苯(V(乙腈):V(甲苯)=1:3)洗脱,采用气相色谱-氮磷检测器(GC-NPD)测定.方法的回收率在62.8%～109.1%之间,相对标准偏差小于14.7...     

食品包装材料中13种增塑剂的毛细管气相色谱法测定

建立了索氏提取、固相萃取净化浓缩、毛细管气相色谱法测定塑料食品包装材料中13种增塑剂的方法.优化了固相萃取淋洗剂、洗脱剂和洗脱剂体积等参数.样品经正己烷索氏提取后,用硅胶小柱净化浓缩.以正己烷-甲苯为淋洗剂,2 mL乙酸乙酯为洗脱剂.过滤后的洗脱液用气相色谱仪分析.结果显示,13种增塑剂在0.1～1000 mg/L范围...     

固相萃取-气相色谱法测定茶叶中多种有机磷农药残留量

本文选择石墨碳黑固相萃取小柱对茶叶样品进行净化,样品中残留的农药经过乙腈洗脱,浓缩后采用气相色谱-火焰光度检测器(FPD)测定.研究结果表明,茶叶中添加农药浓度为0.02～1.0 mg/kg时,9种农药的平均回收率为75.76%～107.9%,相对标准偏差为1.38%～8.95%,方法检出限为0.006～0.01 mg...     

固相萃取-高效液相色谱法同时测定牛奶中残留的9种磺胺类药物

建立了同时测定牛奶中残留的9种磺胺类药物的固相萃取-高效液相色谱分析方法。牛奶样品经磷酸盐缓冲液稀释后高速离心去除脂肪,过C18小柱,用水淋洗,甲醇洗脱,洗脱液经氮气吹干后用乙酸乙酯溶解,并过氨基固相萃取小柱净化,用正己烷及水淋洗,以甲醇-乙腈-水（含1%乙酸）(体积比为1∶1∶8)洗脱,洗脱液用于高效液相色谱分析。采用Inertsil ODS-3 C18柱分离,以水-乙酸和甲醇-乙腈为流动相进行梯度洗脱,二极管阵列检测器检测,外标法定量。9种磺胺类药物标准曲线的线性回归系数均在 0.9999 以上,线性范围为25～5000 μg/L,检出限为1.7～2.8 μg/L,定量限为5.7～9.2 μg/L。在10,20,40 μg/L 添加水平下的添加回收率为72.1%~88.3%,相对标准偏差为2.3%～5.0%。该方法具有快速、灵敏的特点,符合现行兽药残留分析的要求。     

固相萃取-毛细管气相色谱法测定茶叶中11种残留有机磷农药

应用毛细管柱气相色谱法结合固相萃取分离测定了各种茶叶中11种残留农药.样品用乙腈进行超声萃取,萃取液中的农药经过ODS-C18固相萃取柱富集并净化,用甲醇作淋洗剂,洗脱液中各农药经HP-5石英毛细管色谱柱分离后用氮磷检测器进行检测.各农药在一定浓度范围内保持线性关系,分别对方法的回收率及精密度作了试验,回收率在85.3%～100.6%之间,相对标准偏差(n=7)在3.5%～8.4%之间,用此方法分析了9种茶叶样品并列表给出其农药残留量.     

凝胶净化-毛细管气相法测定黄瓜、番茄和青椒中15种有机磷农药

 建立了凝胶柱净化蔬菜样本,毛细管气相 火焰光度检测器测定15种有机磷农药的方法。用环己烷 乙酸乙酯(体积比为1∶1)淋洗液以1mL/min的流量洗脱凝胶柱(10mmi d ×200mm,SX 3),分别用气相检测各段流出液中农药的含量,得到了15种有机磷农药的凝胶流出曲线。采用该方法检测,15种有机磷农药在黄瓜、番茄和青椒中的最小检出质量比均低于5×10-3mg/kg,在蔬菜中不同添加浓度的平均回收率为77 8%～106%,相对标准偏差(RSD)为0 10%～16 6%,其准确度和精密度均达到了农药残留分析的要求。     

固相萃取-气相色谱法同时测定花生中18种有机氯农药残留

利用气相色谱(GC)建立了花生中18种有机氯农药同时测定的方法。花生中有机氯农药残留通过乙腈提取,减压浓缩后过弗罗里固相萃取柱净化,采用正己烷-丙酮(体积比为9∶1)溶液淋洗,淋洗液氮吹近干后以正己烷定容,应用微池电子捕获检测器(μECD)检测。氟氯氰菊酯和溴氰菊酯的检出限分别为50和100g/kg,其余16种有机氯农药检出限均为10μg/kg。在花生样品中添加检测限水平有机氯混标溶液,加标回收率为71.28%～116.58%,测定结果的相对标准偏差为4.08%～18.16%(n=4或5)。     

气相色谱-质谱法测定茶叶中的25种有机氯农药残留

利用气相色谱-质谱(GC-MS)联用技术建立了茶叶中25种有机氯农药残留同时测定的方法。茶叶样品中有机氯农药残留通过正己烷-丙酮(体积比为2∶1)溶液提取,浓缩后过弗罗里硅土柱净化,采用正己烷-乙酸乙酯(体积比为9∶1)溶液淋洗,GC-MS选择离子监测模式(SIM)检测。方法的线性范围为0.010～0.500 mg/L。在茶叶样品中0.01～0.20 mg/kg加标水平下有机氯混标的加标回收率为70.8%～105.5%,相对标准偏差为1.6%～12.7%。除硫丹Ⅰ和硫丹Ⅱ的定量限为0.02 mg/kg以外,其余23种有机氯农药的定量限均为0.01 mg/kg。     

多壁碳纳米管固相萃取/超高效液相色谱-串联质谱测定茶油中12种氨基甲酸酯类农药

建立了多壁碳纳米管(MWCNTs)为吸附剂的固相萃取净化/超高效液相色谱-串联质谱(UPLC-MS/MS)检测茶油中12种氨基甲酸酯类农药残留的快速分析方法。样品经乙腈超声提取,MWCNTs固相萃取小柱净化,以乙腈进行洗脱,旋蒸浓缩后以0.1%乙酸-乙腈(5∶5,体积比)定容,采用UPLC-MS/MS多反应监测模式(MRM)测定,外标法定量。考察了提取方式、吸附材料类型、洗脱溶剂用量等因素对目标物萃取效率的影响。在优化实验条件下,MWCNTs固相萃取小柱对茶油样品的净化效果理想。12种氨基甲酸酯类农药在0.005～0.1μg/mL范围内线性关系良好,相关系数(r)均不小于0.998 88;在0.01、0.025、0.05 mg/kg加标水平下,12种目标物的平均回收率为78.3%～116%,相对标准偏差为2.6%～12%,方法的定量下限为0.2～3.0μg/kg。     

Determination of residues of 446 pesticides in fruits and vegetables by three-cartridge solid-phase extraction-gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry

A method was developed for determination of residues of 446 pesticides in fruits and vegetables through the use of cleanup by a 3-cartridge solid-phase extraction-gas chromatography/ mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Fruit and vegetable samples (20 g) were extracted with 40 mL acetonitrile, salted out, and centrifuged. Half of the supernatant was passed into an Envi-18 cartridge, eluted with acetonitrile, and cleaned up with Envi-Carb and aminopropyl Sep-Pak cartridges in series after concentration of the eluates. Pesticides were eluted with acetonitrile-toluene (3 + 1, v/v), and eluates were concentrated to 0.5 mL and then added into internal standards after solvent exchange with 2 mL hexane and used for determination of 383 pesticides by GC/MS. The other half of the supernatant was concentrated to 1 mL and cleaned up with Envi-Carb and aminopropyl Sep-Pak cartridges in series. Pesticides were eluted with acetonitrile-toluene (3 + 1, v/v), and the eluates were concentrated to 0.5 mL, dried with nitrogen gas, diluted to 1.0 mL with acetonitrile-water (3 + 2, v/v), and used for determination of 63 pesticides by LC/MS/MS. The limit of detection for the method was 0.2-600 ng/g depending on the individual pesticide. In the method, fortification recovery tests at high, medium, and low levels were conducted on 6 varieties of fruits and vegetables, i.e., apples, oranges, grapes, cabbage, tomatoes, and celery, with average recoveries falling within the range of 55.0-133.8% for 446 pesticides, among which average recoveries between 60.0-120.0% accounted for 99% of the results. The relative standard deviation was between 2.1-39.1%, of which a relative standard deviation of 2.1-25.0% made up 96% of the results. Experiments proved that the method was applicable for determination of residues of 446 pesticides in fruit and vegetables.     

Determination of organophosphorus pesticide residues in the roots of Platycodon grandiflorum by solid-phase extraction and gas chromatography with flame photometric detection

A simple and rapid sample preparation method using accelerated solvent extraction and solid-phase extraction (SPE) cleanup for determining organophosphorus (OP) pesticides in the roots of Platycodon grandiflorum was developed. The OP pesticides were concentrated by use of an SPE cartridge (ENVI-Carb) and quantitatively analyzed and confirmed by capillary gas chromatography with flame photometric detection. The pesticides were eluted from the cartridges with 20 mL acetonitrile-toluene (3 + 1, v/v). The average recovery from 10 g PF grandiflorum roots, fortified at 3 levels ranging from 0.04 to 1.00 mg/kg, was 91.9% with a relative standard deviation of 4.3%. The limits of detection ranged from 1.16 x 10(-3) mg/kg (dimethoate) to 4.64 x 10(-3) mg/kg (dichlorvos). The proposed method showed acceptable accuracy and precision while minimizing environmental concerns, time, and labor.     

Simultaneous determination of 405 pesticide residues in grain by accelerated solvent extraction then gas chromatography-mass spectrometry or liquid chromatography-tandem mass spectrometry

A new method has been established for simultaneous determination of 405 pesticide residues in grain, using accelerated solvent extraction (ASE), solid-phase extraction (SPE), and GC-MS and LC-MS-MS. The method was based on appraisal of the GC-MS and LC-MS-MS characteristics of 660 pesticides, their efficiency of extraction from grain, and their purification. Samples of grain (10 g) were mixed with Celite 545 (10 g) and the mixture was placed in a 34-mL cell of an accelerated solvent extractor and extracted with acetonitrile in the static state for 3 min with two cycles at 1,500 psig and at 80°C. For the 362 pesticides determined by GC-MS, half of the extracts were cleaned with an Envi-18 cartridge and then further cleaned with Envi-Carb and Sep-Pak NH₂ cartridges in series. The pesticides were eluted with acetonitrile-toluene, 3:1, and the eluates were concentrated and used for analysis after being exchanged with hexane twice. For the 43 pesticides determined by LC-MS-MS the other half of the extracts were cleaned with Sep-Pak Alumina N cartridge and further cleaned with Envi-Carb and Sep-Pak NH₂ cartridges. Pesticides were eluted with acetonitrile-toluene, 3:1. After evaporation to dryness the eluates were diluted with acetonitrile-water, 3:2, and used for analysis. In the linear range of each pesticide the linear correlation coefficient r was equal to or greater than 0.956 and 94% of linear correlation coefficients were greater than 0.990. At low, medium, and high fortification levels, at the limit of detection (LOD), twice the LOD and ten times LOD, respectively, recoveries ranged from 42 to 132%; for 382 pesticides, or 94.32%, recovery was from 60 to 120%. The relative standard deviation (RSD) was always below 38% and was below 30% for 391 pesticides, or 96.54%. The LOD was 0.0005–0.3000 mg kg⁻¹. The proposed method is suitable for determination of 405 pesticide residues in grain such as maize, wheat, oat, rice, and barley, etc.      

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。     

液相色谱-四极杆-飞行时间质谱法快速筛查与确证紫甘蓝中415种农药残留

应用液相色谱-四极杆-飞行时间质谱(LC-QTOF/MS)建立了一次进样可同时对紫甘蓝中415种农药残留进行快速筛查和准确确证的分析方法。实验采用1%(v/v)醋酸乙腈溶液提取,无水硫酸镁和氯化钠进行盐析,ZORBAX SB-C18色谱柱(100 mm×2.1 mm, 3.5 μm)分离,以0.1%(v/v)甲酸水溶液(含5 mmol/L乙酸铵)-乙腈为二元流动相进行梯度洗脱,应用LC-QTOF/MS在电喷雾电离、全离子MS/MS(All Ions MS/MS)扫描正模式下进行检测,基质匹配外标法定量分析。通过优化全自动MS/MS采集模式(Auto MS/MS)和全离子MS/MS采集模式下的不同参数,得到每种采集模式下的最佳条件。然后在2种不同采集模式的最佳条件下对比,最终选取All Ions MS/MS采集模式。实验结果表明,采用所建立的分析方法可以准确定性和定量筛查紫甘蓝中415种农药残留,所有415种农药在各自的范围内线性相关系数(r²)均大于0.990,其中411种农药的筛查限(SDL)≤5 μg/kg, 413种农药的定量限(LOQ)≤10 μg/kg。在1倍、2倍和10倍LOQ添加水平下,农药的回收率分别为65.7%~118.4%、72.0%~118.8%和70.2%~111.2%,相对标准偏差分别为0.9%~19.7%、0.2%~19.9%和0.6%~19.9%。将该方法应用于2019年欧盟能力验证项目的紫甘蓝样品中未知农药残留筛查方法和定量方法考核样的检测,所有添加农药均被准确定性筛查和定量检测,没有假阳性和假阴性。结果表明,该方法快速、准确、可靠,适用于对紫甘蓝中多种农药残留的高通量定性筛查和准确定量,可以扩展到其他果蔬基质中多农残的高通量筛查。     

超高效液相色谱-四极杆-飞行时间质谱法快速筛查茶叶中的204种农药残留

利用超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF/MS)技术建立了茶叶中204种农药残留的快速筛查和确证检测方法。样品采用乙腈提取,经Carb-PSA固相萃取小柱净化,用乙腈-甲苯(3:1, v/v)洗脱,采用UPLC-Q-TOF/MS检测,外标法定量。建立了204种农药的一级精确质量数据库和二级谱图库,通过化合物的精确质量数、保留时间、同位素比值等信息对检测结果进行自动检索,从而在无对照标准品的情况下完成了204种农药的定性鉴定。结果表明,该方法可以同时对茶叶中204种农药残留进行快速筛查,在10、20、50 μg/kg 3个添加水平下的平均回收率为68.1%~117.2%,相对标准偏差为3.1%~18.9%。定量限均小于10 μg/kg。采用本方法对4份阳性样品进行检测,所得结果与GB/T 23205-2008的检测结果基本一致。该方法快速、灵敏、准确,可用于茶叶中204种农药残留的快速筛查。     

液相色谱-串联质谱法快速筛查测定浓缩果蔬汁中的156种农药残留

建立了浓缩果蔬汁中156种农药多残留的液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)测定方法。样品用1%醋酸乙腈溶液萃取,经Waters Sep-Pak Vac固相萃取柱净化,乙腈-甲苯(体积比为3∶1)洗脱,旋转蒸发浓缩,用乙腈-水（体积比为3∶2）溶解,以Agilent ZORBAX SB-C18色谱柱分离,以电喷雾电离串联质谱在正离子多反应监测(MRM)模式下进行测定。对156种农药在5种浓缩果蔬汁(橙汁、苹果汁、葡萄汁、白菜汁、胡萝卜汁)中两个添加水平下的回收率进行了测定,回收率范围为57.2%～122.7%,相对标准偏差范围为0.9%～19.8%。方法的检出限(S/N=3)和定量限(S/N=10)范围分别为0.10～56.77 μg/kg和0.33～189.23 μg/kg。该方法样品前处理简单、快速、分析时间短,灵敏度、准确度和精密度均符合农药多残留检测技术的要求,适用于苹果汁、橙汁、葡萄汁、白菜汁、胡萝卜汁等浓缩果蔬汁中156种农药多残留的快速筛查测定。     

气相色谱-电子轰击离子源质谱法分析卷烟和烟叶中29种农药的残留

开展了卷烟和烟叶中有机氯、有机磷和拟除虫菊酯3类29种农药残留的气相色谱-电子轰击离子源质谱(GC-EI/MS)的分析方法研究。优化与选择了卷烟和烟叶样品的前处理条件,样品经正己烷-丙酮(体积比为1∶1)混合提取剂超声提取、Florisil硅土和中性氧化铝双净化剂固相萃取柱净化、二氯甲烷-正己烷(体积比为95∶5)混合洗脱剂洗脱和浓缩后,以磷酸三苯酯(TPP)为内标物,采用GC-EI/MS的选择离子监测方式(SIM)进行定性和定量分析。当样品的加标水平为20,50,100 μg/kg时,加标回收率为70%～110%,相对标准偏差在2%～8%之间;除了甲氰菊酯、氯菊酯和溴氰菊酯的方法检出限(LOD)分别为1.85,1.74与2.54 μg/kg外,其余的26种农药的LOD均小于0.8 μg/kg;线性范围为5.0～500.0 μg/kg,相关系数都大于等于0.9994。此分析方法已成功地应用于卷烟和烟叶样品中3类29种痕量农药残留的分析     

液相色谱-电喷雾串联质谱法测定生姜中的215种农药残留

建立了生姜中215种农药多残留测定的液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)方法。样品用1%醋酸-乙腈溶液均质提取,经Sep-Pak Vac固相萃取柱净化,乙腈-甲苯(3:1, v/v)洗脱,旋转蒸发浓缩至约0.5 mL后,于室温氮气吹干,用乙腈-水(3:2, v/v)溶解,以电喷雾电离串联质谱在正离子多反应监测(MRM)模式下进行测定。在定量限水平进行添加回收率实验,方法的回收率范围为68.1%～132.6%,其中回收率在70%～120%的占94.4%,相对标准偏差(RSD)范围为0.4%～25.0%。方法的检出限(S/N=3)和定量限(S/N=10)范围分别为0.01～70.45 μg/L和0.04～234.84 μg/L。该方法操作简便,灵敏度、准确度和精密度均符合农药多残留检测技术要求,适用于生姜中215种农药多残留的快速测定。