分散液相微萃取-气相色谱联用分析水样中菊酯类农药残留

将分散液-液微萃取(DLLME)与气相色谱-电子俘获检测(GC-ECD)技术相结合,建立了高灵敏度测定水样中7种菊酯类农药残留的新方法。对影响萃取富集效率的因素进行优化,萃取条件选定为:在5.0mL样品溶液中加入10.0μL氯苯和1.0mL丙酮,分散混匀后,以5000r/min离心5min,吸出萃取溶剂氯苯直接进样分析。在优化条件下7种菊酯类农药的富集倍数高达708～1087倍。以α-六六六为内标,7种菊酯类农药在0.8～600μg/L范围内具有良好的线性关系,线性相关系数在0.9990～0.9999之间;检出限为0.04～0.10μg/L(S/N=3)。本方法已应用于自来水、井水及河水等实际水样的分析,平均加标回收率在76.0%～116.0%之间;相对标准偏差在3.1%～7.2%之间。方法具有操作简单、富集效率高和灵敏度高等特点,可满足水样中菊酯类农药残留的检测要求。     

低温富集液液萃取-气相色谱-串联质谱法测定水样中15种农药残留

利用低温冷冻条件下农药在水相和有机相之间达到新的传质平衡,建立了低温富集液液萃取-气相色谱-三重四极杆串联质谱法同时测定水样中15种有机磷、有机氯及菊酯类农药的方法。通过对样品前处理中的溶剂选择、冷冻温度及冷冻时间的优化,最终确定的样品前处理条件为:萃取溶剂为甲苯2.0 mL;冷冻温度-40℃;冷冻时间1h。15种农药的检出限(3S/N)在0.005~0.02μg·L-1范围,测定下限(10S/N)为0.02~0.07μg·L-1。方法用于水样中农药的分析,加标回收率在78.8%~124%之间,测定值的相对标准偏差(n=5)在0.9%~9.1%之间。     

液-液萃取富集-气相色谱法测定水中有机氯农药和多氯联苯

采用正己烷作萃取溶剂提取并富集水样中有机氯农药(OCP's)和多氯联苯(PCB's),所得提取液经浓缩至约0.5mL并定容至1.0mL后,用气相色谱法-电子捕获检测器测定水中有机氯农药和多氯联苯。采用Rtx-5MS和Rtx-1701双柱法根据与标准物质的保留时间相对比进行定性分析;采用Rtx-5MS柱对被测组分按外标法进行定量分析。结果表明:各种农药质量浓度均在0.5～40μg·L~(-1)范围内与峰面积呈线性关系。有机氯农药和多氯联苯的检出限(3s)在0.001 1～0.004 7μg·L~(-1)之间。用标准加入法测得其回收率在83.3%～112.1%之间,相对标准偏差(n=7)在4.4%～9.4%之间。     

固相萃取-在线凝胶渗透色谱-气相色谱-串联质谱法测定水中31种有机氯农药

建立了固相萃取(SPE)-在线凝胶渗透色谱(GPC)-气相色谱-串联质谱法(GC-MS/MS)测定水中31种有机氯农药(OCPs)含量的方法,并用于福建各地水样的分析。水样以10 mL·min~(-1)速率过SPE柱,吹氮10 min除去水分,用5 mL二氯甲烷以1.0 mL·min~(-1)速率过柱洗脱目标物,样品瓶隔夜沥干,用5 mL二氯甲烷分2次洗涤,洗涤液合并至洗脱液中,吹氮至0.5 mL,供在线GPC净化和GC-MS/MS分析。在线GPC净化中采用GLNpak EV-200色谱柱和体积比为3∶7的丙酮-环己烷混合液;气相色谱以SH-Rxi-5Sil MS型毛细管色谱柱为固定相,在程序升温下进行色谱分离;串联质谱以电子轰击离子(EI)源电离,在多反应监测模式下检测;以基质匹配混合标准溶液系列制作工作曲线,外标法定量。结果显示:水中31种OCPs的质量浓度和其对应的峰面积均在一定范围内呈线性关系,检出限为0.3～8.3 ng·L~(-1)。对实际水样进行3个浓度水平的加标回收试验,31种OCPs的回收率为67.0%～123%,测定值的相对标准偏差(n=6)为3.9%～20%。用此方法分析福建省11个地区枯水期的水样(包括海水、地表水和工业废水),结果显示:福建省枯水期各水体中OCPs的检出量为5.2～125.6 ng·L~(-1),宁德三都澳(海水)检出OCPs的种类较多(11种),与福建省2006年以前文献报道的数据相比,OCPs检出量较低,且均低于中国或权威组织机构标准规定的限值。     

固相膜萃取富集大体积地下水中痕量半挥发性有机污染物

研究了用C18固相膜萃取法(SPE)富集大量地下水样中半挥发性有机污染物,试验中以有机氯药(OCP's)及多环芳(PAH's)作为试验对象的现场采样富集,并以气相色谱-质谱法完成其定性及定量测定.对SPE的多项参数,诸如萃取率、检出限及测定限以及准确度和精密度均作了测试.在与液-液萃取(LLE)所作的对比试验所得到的结果表明:SPE法的回收率为79.1%～103.7%(OCP's)和72.4%～119.2%(PAH's);相对标准偏差为6.4%～16.7%(OCP's)和3.4%～20.2%(PAH's).SPE法之优于LLE法主要在于分析过程快速,有机溶剂使用量大大减少,方法更适合于大量水样中有机污染物的现场取样处理.     

固相萃取-气相色谱/质谱选择离子检测法测定水中27种有机农药EI北大核心CSCD

采用固相萃取(SPE)技术,结合气相色谱/质谱(GC-MS)选择离子检测法(SIM)对水中27种有机农药进行提取、净化、浓缩前处理,实验优选出了分离效果较好的色谱柱VF-1701 ms(30 m×0.25 mm×0.25μm),优化了固相萃取及GC-MS的分析条件,建立了水样中7类27种有机农药的SPE-GC-MS/SIM分析方法。样品中各组分曲线相关系数R2均大于0.9981,检测限为0.015~0.054μg/L,平均加标回收率为72.8%~110.8%,相对标准偏差RSD为5.5%~16%。与传统方法相比,该法无需对有机污染物进行分类处理,可以同时快速测定7类27种有机农药。     

固相萃取-气相色谱/质谱选择离子检测法测定水中27种有机农药EI北大核心CSCD

采用固相萃取(SPE)技术,结合气相色谱/质谱(GC-MS)选择离子检测法(SIM)对水中27种有机农药进行提取、净化、浓缩前处理,实验优选出了分离效果较好的色谱柱VF-1701 ms(30 m×0.25 mm×0.25μm),优化了固相萃取及GC-MS的分析条件,建立了水样中7类27种有机农药的SPE-GC-MS/SIM分析方法。样品中各组分曲线相关系数R2均大于0.9981,检测限为0.015~0.054μg/L,平均加标回收率为72.8%~110.8%,相对标准偏差RSD为5.5%~16%。与传统方法相比,该法无需对有机污染物进行分类处理,可以同时快速测定7类27种有机农药。     

固相萃取/高效液相色谱-串联质谱法同时检测环境水样中24种农药残留

建立了一种固相萃取/高效液相色谱-串联质谱(SPE/HPLC-MS/MS)同时检测水体中24种农药的分析方法。样品用乙腈提取后,经固相萃取小柱富集净化。以乙腈-0.1%(体积分数)甲酸水溶液为流动相梯度洗脱,在电喷雾离子源正离子模式下(ESI+)采用多反应监测(MRM)模式检测。结果显示,24种农药在1~200μg/L范围内具有良好的线性关系,相关系数(r2)均不小于0.998,水样中3个添加水平(5、20、100μg/L)下的回收率为65.9%~127.8%,相对标准偏差(RSD)为0.7%~14.2%;方法检出限为0.05~0.71 ng/L。采用该方法对大连地区10个河流入海口及2个水库的水样进行了检测,12个站位的样品中共检出10种农药,质量浓度为0.2~558.3 ng/L。结果表明,所建立的SPE/HPLC-MS/MS方法高效、灵敏、可靠,可用于实际水体中多种农药的同时检测。     

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。     

C18修饰的磁性纳米材料用于不同性质农药的固相萃取理论研究与应用

将C18修饰的磁性纳米材料用于大体积水样中不同性质低浓度农药的分散固相萃取,并采用GC-MS进行检测。理论推导了样品添加回收率与磁性纳米颗粒密度、半径和用量之间的关系。当水样体积一定时,吸附材料用量越大,回收率越高,与实验结果一致。优化条件下,在0.1~10μg/L范围内线性相关系数大于0.9975(甲草胺除外,R2=0.9684)。方法检出限(S/N=3)在0.006~0.05μg/L之间;回收率在13.4%~121.8%之间,标准偏差低于8.2%;最高富集倍数可达1484(氰戊菊酯)。方法可应用于大体积水样中低浓度非极性农药组分的检测。     

Determination of nine emerging pesticides at trace level in aqueous samples using fully automated on-line solid phase extraction coupled with liquid chromatography-mass spectrometry

On-line solid phase extraction (SPE) coupled to liquid chromatography-mass spectrometry (LC-MS) offers an easy and fast strategy to analyze the organic contaminants in environmental samples with high sensitivity and selectivity. This paper described an in-house designed on-line SPE system and an on-line SPE-LC-MS method for the determination of pesticides at trace levels in water samples. The system was assembled from an eight-position valve, a piston pump, a six-port valve and a C18 SPE column, and significantly reduced analysis time by achieving full automation. Moreover, the use of a large enrichment volume (50?mL) significantly enhanced method sensitivity. Using this on-line SPE system, an on-line SPE-LC-MS method was developed for the determination of nine pesticides at trace levels in lake water and seawater sample. Under optimized conditions, method detection limits (MDLs) were 1.00–10.0?ng?L^?1.     

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。     

快速滤过型净化结合气相色谱-串联质谱法同时检测茶叶中10种拟除虫菊酯农药残留

建立了快速滤过型净化（m-PFC）结合气相色谱-串联质谱（GC-MS/MS）测定茶叶中10种拟除虫菊酯类农药残留的方法。比较了采用不同提取溶剂（乙腈、丙酮和乙酸乙酯）和不同提取方式（不加水浸泡和加水浸泡）时10种农药的提取效率；比较了2种QuEChERS净化管和m-PFC柱对茶叶提取液的净化效果和农药残留的回收率。结果表明，茶叶样品不加水浸泡，用乙腈提取效果最好；m-PFC柱对茶叶提取液净化效果良好，而且能保证较高的农药回收率。10种拟除虫菊酯农药在相应的范围内有良好的线性关系，相关系数（R²）大于0.9980；10种农药在4个水平添加下的回收率为87.5%~111.3%，RSD为2.1%~8.9%。方法的检出限为0.001~0.015 mg/kg，定量限为0.003~0.05 mg/kg。利用该方法检测市售50例茶叶样品中10种拟除虫菊酯农药的残留，检出率为48%，但农药残留量均在国家标准限量值以下。与传统QuEChERS法和固相萃取法相比，该方法具有操作简单、准确度和精密度良好等优点，为多种拟除虫菊酯类农药在茶叶中的残留测定提供了快速检测的新方法。     

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.     

固相萃取-气相色谱-质谱联用同时测定河水和海水中87种农药

采用固相萃取-气相色谱-质谱联用技术,建立了河水和海水中87种农药(24种有机磷、15种有机氯、12种唑类、9种拟除虫菊酯类、5种氨基甲酸酯类、7种酰胺类及15种其他新型农药)的多残留同时分析方法。优化了影响分离效果和灵敏度的仪器参数,考察了固相萃取柱柱型及水样体积、pH、盐度的影响,采用NH2柱优化了净化效果,内标法和替代物法用于数据的质量控制。结果表明: 在最佳条件下,各目标农药的方法检出限为0.1～6.6 ng/L;以实际河水和海水为基底,在5 ng/L和20 ng/L的加标水平下,绝大多数目标农药的回收率为60%～120%,相对标准偏差(n=4)为0.01%～9.7%。该法灵敏、准确,已成功地应用于福建九龙江河口区表层水样中多种类农药的复合污染监测,检出包括5种有机磷类、3种酰胺类、4种唑类、3种氨基甲酸酯类、2种拟除虫菊酯类等农药20种。     

Establishment of trace determination method of pyrethroid pesticides with TiO2 nanotube array micro-solid phase equilibrium extraction combined with GC-ECD

This paper described a new method for the enrichment and determination of pyrethroid pesticides from environmental water samples with ordered TiO(2) nanotube array micro-solid phase equilibrium extraction (μ-SPEE) prior to gas chromatography (GC) with electron capture detection (ECD). Several factors such as the anodization voltage, the kind of organic solvents, sample pH, equilibrium extraction time, desorption time and salting-out effect were optimized. Under the optimal conditions, ordered TiO(2) nanotube arrays demonstrated excellent merits on the preconcentration of pyrethroid pesticides and good detection limits were achieved as 0.018, 0.020, 0.031, 0.041, and 0.070 μg L(-1) for bifenthrin, fenpropathrin, cyhalothrin, fenvalerate, and deltamethrin, respectively. Four real water samples were used to validate the proposed method and the spiked recoveries were over the range of 81.9-110.6%. Compared to conventional solid phase extraction (SPE), the present method showed better recoveries and good reproducibility. These results showed that this μ-SPEE technique could be an important alternative to multistep SPE for the extraction and determination of such analytes in complex samples and become a useful tool in monitoring such analytes in the environment.     

Simultaneous determination of selected endocrine disrupters (pesticides,phenols and phthalates) in water by in-field solid-phase extraction (SPE) using the prototype PROFEXS followed by on-line SPE (PROSPEKT) and analysis by liquid chromatography-atmospheric pressure chemical ionisation-mass spectrometry

In this study, a new procedure, based on on-line solid-phase extraction (SPE) and analysis by liquid-chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS), has been developed for the simultaneous, multianalyte determination of 21 selected pesticides, phenols and phthalates in water. SPE was carried out on polymeric PLRP-s cartridges by percolating 20 mL-samples. For sample preconcentration, the performance of a prototype programmable field extraction system (PROFEXS) was evaluated against the commercial laboratory bench Prospekt system used for method development. The Profexs is designed for the automated on-site sampling, SPE preconcentration, and storage of up to 16 samples in SPE cartridges. These cartridges are further eluted and on-line analyzed with the Prospekt coupled to the chromatographic system. In the optimized method, where completely on-line SPE-LC-MS analysis of the samples is carried out with the Prospekt in the laboratory, detection limits lower than 100 ng/L, and satisfactory precision (relative standard deviations <25%) and accuracies (recovery percentages >75%) were obtained for most investigated compounds from the analysis of spiked Milli-Q water. The extraction efficiency achieved with the Profexs was comparable to that of the Prospekt for most compounds and somewhat lower for the most apolar analytes, probably due to adsorption on the pump filters. The completely on-line optimized method was applied to the analysis of surface water, ground water and drinking water from a waterworks in Barcelona. Some pesticides and phenols were found in both surface water and groundwater at ng/L or µg/L levels, but not in the final drinking water. Di(2-ethylhexyl)phthalate (DEHP) was present in all samples investigated, including blanks. To the author's knowledge, this is the first work describing the application of a fully automated on-line SPE-LC-MS method for the simultaneous analysis of pesticides, phenols, and phthalates in water, and the second one that examines the possibilities of the prototype Profexs for automated on-site SPE preconcentration of organic pollutants from water samples.     

气相色谱法测定地表水中拟除虫菊酯类农药残留

建立了气相色谱检测地表水样中痕量氯氟氰菊酯、氯氰菊酯、氰戊菊酯和溴氰菊酯农药残留的分析方法。水样经环己烷液液萃取、无水硫酸钠过滤,再用N-丙基乙二胺和无水硫酸镁净化,用氮气吹干浓缩,再用正己烷溶解,离心分离后取上清液进样,以气相色谱法测定4种拟除虫菊酯的含量。4种拟除虫菊酯化合物的质量浓度在5~200μg/L范围内与色谱峰面积成良好的线性关系,相关系数均大于0.999,方法检出限为0.03~0.09μg/L,模拟水样的平均加标回收率为98.0%~104.5%,相对标准偏差为0.89%~6.44%(n=6)。该方法操作方便、快速,结果准确、可靠,有机溶剂用量少,适用于水中拟除虫菊酯类农药残留的测定。     

加速溶剂萃取-固相萃取净化-气相色谱-串联质谱法检测茶叶中9种拟除虫菊酯类农药残留

建立了加速溶剂萃取（ASE）-固相萃取净化（SPE）-气相色谱-串联质谱（GC-MS/MS）同时测定茶叶中9种拟除虫菊酯类农药残留的方法。ASE萃取溶剂为丙酮-正己烷（1：1,v/v）,萃取温度为100℃,萃取压力为10 MPa,加热时间为3 min,静态萃取时间为5 min,循环1次,冲洗体积为40%萃取池体积,氮气吹扫100 s。萃取结束后用Cleanert TPT固相萃取柱净化,净化液浓缩定容后,采用GC-MS/MS测定,外标法定量。9种拟除虫菊酯类农药在2~1000 μg/L范围内呈现良好的线性关系,相关系数（r²）均大于0.99,方法检出限为0.2~4.5 μg/kg,定量限为0.8~15.0 μg/kg。在绿茶、红茶空白基质中做加标回收试验,添加水平为0.02、0.1、0.4 mg/kg以及定量限水平,得到的平均回收率为69.87%~110.0%,相对标准偏差（RSD）为0.7%~11.2%。该方法背景干扰低、灵敏度高、重现性好、回收率稳定,适用于茶叶中拟除虫菊酯类农药残留量的检测。