环境水中农药残留检测的富集净化过程综述

环境水中农药残留量极低,远低于仪器的检出限而无法直接检测,其瓶颈在于如何富集水中的目标物。本文综述了近年来环境水中农药残留检测预处理富集与净化技术的研究进展;重点讨论了液-液萃取法中萃取溶剂的选择、振荡方式、浓缩方式、乳化与盐析现象、pH值、提取液的净化等影响因素;固相萃取法中吸附材料的选择及活化过程、穿透体积、过水流量、水分的去除、固相萃取柱的淋洗、目标化合物的洗脱、 pH与NaCl改进剂、洗脱液的净化等影响因素;简要介绍新型富集方法并探讨了其中存在的不足;展望了环境水中农药残留富集净化技术的发展方向。     

Recovery of high purity plumbagin from Drosera intermedia

In this study a simple process encompassing an efficient extraction and fractionation method to obtain high purity plumbagin from micropropagated D. intermedia plants is described. Plumbagin is a naphthoquinone derived from a diverse but restricted group of plant species that includes the Drosera spp. and is in demand for pharmacological research. It was brought initially to the attention of researchers due to its broad antimicrobial and antitumor properties but has continued to find application against new pharmacological targets. The procedure described in this work involved testing four extraction methods to maximize product recovery and separating the 30-50% acetonitrile in water fraction (v/v) on a SPE column followed by lyophilisation. By applying ultrasonic treatment to the plant matrix leached in n-hexane followed by a single step purification process, 2.74 mg of plumbagin per gram of plant material could be obtained with a recovery of 86.3% and over 99% purity.     

Determination of Rotenone Residues in Foodstuffs by Solid-Phase Extraction （SPE） and Liquid Chromatography/Tandem Mass Spectrometry （LC-MS/ MS）

We developed a novel approach to determine rotenone residues in foodstuffs, by integrating solid-phase extraction （SPE） and liquid chromatography/tandem mass spectrometry （LC-MS/MS） technologies, to achieve high sensitivity and selectivity. In our method, the solvent extraction with n-hexane-dichloromethane （50：50, v/v） and cleanup with florisil SPE cartridges using ethyl acetate-ethyl ether （25：75, v/v） as eluents provided adequate recovery of rotenone. The detection of rotenone was then carried out by LC-MS/MS using acetonitrile-water with the 0.1% formic acid （w/v） as the mobile phase. The multiple reaction monitoring （MRM） scheme employed in the approach involved the transitions of the precursor ion to three selected product ions, in which one pair for quantification was m/z 395.3 〉 213.2 and the other two pairs for identification were m/z 395.3 〉 192.2 and 395.3 〉 367.0. The limits of quantification （LOQs） of the method ranged from 0.001 to 0.005 mg kg-1 depending on the matrix. Intra- and inter-day precisions （relative standard deviations, RSDs） for rotenone were less than 7.1 and 14.8%, respectively. Results from repetitive analysis suggested good reproducibility of the method for rotenone residue detection. The recoveries at three concentrations （LOQ, 10LOQ and 100LOQ） ranged from 79.3-118.3% in cabbage, potato, onion, carrot, apple, orange, banana, lichee, tea, and Shiitake mushroom. The proposed procedure was then applied to the analysis of 129 real samples collected from Xiamen, Fujian Province, China. The existence of rotenone was found in two tea products with concentrations of 0.012 and 0.016 mg kg-1, respectively. The method has great potential for routine analysis of monitoring rotenone residue in foodstuffs.     

固相萃取-高效液相色谱法测定城市污水中痕量多环芳烃的研究

[目的]采用固相萃取-高效液相色谱法测定城市污水中痕量多环芳烃.[方法]从固相萃取柱、洗脱溶剂、洗脱体积、洗脱速度等方面,对固相萃取-反相高效液相色谱法的试验条件进行优化,并检测城市污水中痕量多环芳烃。[结果]优化得到的固相萃取条件为:选择SUPELCLEAN LC-18固相萃取柱;以二氯甲烷为洗脱溶剂,洗脱体积为15 ml,分3次洗脱,洗脱速度为2 ml/min;上样速度为5ml/min,上样体积为1 000 ml,并向水样添加200 ml甲醇作有机改性溶剂。在该萃取条件下,该方法的加标回收率高,为76.3%～105.2%;相对标准偏差为3.8%～6.0%,精密度好;检出限低,为0.000 8～0.048μg/L。[结论]固相萃取-反相高效液相色谱法操作简便,灵敏度高,精密度好,适用于大体积水样连续测定。     

高效液相色谱法-荧光检测器同时检测龙眼中多菌灵和噻菌灵残留

建立了同时检测龙眼中多菌灵和噻菌灵残留的高效液相色谱方法。样品经乙腈提取,硅胶柱净化,然后采用高效液相色谱法-荧光检测器测定,外标法定量。对样品前处理和色谱分离条件进行了研究和优化。两种杀菌剂在0.01μg/mL～2.00μg/mL范围内线性良好,相关系数分别为0.9990和0.9996。添加两个浓度水平(0.1、0.4μg/mL)两种杀菌剂在龙眼中的回收率均在95.7%～96.2%之间,相对标准偏差不大于2%。方法简便、快速、净化效果较好,可同时满足龙眼中两种杀菌剂残留的检验工作需要。     

固相萃取-高效液相色谱法同时测定水中甲萘威和阿特拉津含量研究

[目的]建立同时测定水中甲萘威和阿特拉津的固相萃取-高效液相色谱法。[方法]利用固相萃取富集浓缩、高效液相色谱柱实现分离、紫外检测器定量检测的方法,同时测定水中甲萘威和阿特拉津含量。[结果]在试验条件下,甲萘威和阿特拉津在0.1~10.0mg/L浓度范围内的标准曲线线性相关系数分别达到0.999 9和0.999 0,相对标准偏差(RSD)分别为0.3%~0.5%和1.0%~3.7%,检出限分别为0.003和0.010μg/L。[结论]该方法具有操作简便、分析结果准确、检出限低等优点,适用于同时测定水中甲萘威和阿特拉津含量。     

油菜化学杂交剂sx-1的残留检测

用乙腈提取样品,弗罗里硅土固相萃取柱净化,waters2695高效液相色谱仪检测,外标法定量,测定了5个甘蓝型油菜叶片及土壤中化学杂交剂sx-1的残留量。结果表明:在0.05～5.00μg/mL苯磺隆添加浓度范围内,样品平均回收率在76.25%～94.59%,变异系数为1.30%～4.77%。该方法对油菜植株体内及土壤中sx-1残留量检测结果均为0。     

分子印记技术在葛根素分离中的应用及溶剂对聚合物识别能力的影响

通过合成分子印记聚合物以实现葛根素的高效分离。通过静态吸附实验对聚合物的吸附性能进行了评价。使用量子化学的方法对模板分子与功能单体的结合构象进行了计算机模拟,采用UV、IR、1HNMR一系列光谱学分析了分子印记聚合物形成的机理,通过固相萃取考察了聚合物对葛根素的选择性能。该分子印记聚合物对葛根素具有高度选择性,一次性处理葛根素的回收率达到78.0%,纯度可达到86.5%。为从葛根中高效分离富集异黄酮活性成分葛根素提供了一种新方法。     

集约化奶牛场沼液沼灌区类固醇雌激素定量分析

随着集约化奶牛场的发展,其产生的类固醇雌激素已成为新的环境污染源,因此建立沼液及土壤复杂组分中类固醇雌激素定量分析方法,考察不同季节类固醇雌激素含量变化十分必要.该研究对奶牛场沼灌区的沼液及土壤中5种类固醇雌激素(雌酮、17α-雌二醇、17β-雌二醇、雌三醇、雌酮硫酸钠)建立了固相萃取-液相色谱串联两级质谱(SPE-L...     

茶叶农药残留检测方法比较研究

试验比较了快速溶剂萃取(ASE)和高速匀浆提取,固相萃取净化(SPE)和凝胶色谱净化(GPC),气相色谱(GC)和气质联用(GC-MS)检测对茶叶中农药残留,建立了茶叶中32种农药残留的检测方法,其中包含了相关标准规定的茶叶所需检测的14种农药、增加了13种高毒农药和5种菊酯类农药。样品采用两种方法提取,两种方法净化,两种仪器检测分析,分别做添加回收试验。结果表明:在0.10 mg/kg添加浓度下作添加回收试验,回收率和相对标准偏差分别为:一般提取和固相萃取净化81.00%～119.80%、1.10～5.42;一般提取和凝胶色谱净化76.47%～93.45%、3.43～7.34;ASE快速萃取和固相萃取净化80.12%～110.30%、1.37～5.32;ASE快速萃取和凝胶色谱净化76.45%～93.56%、2.56～7.98。MDL分别为MSD在0.079～14.40μg/kg、FPD/ECD在0.24～98.0μg/kg。该研究讨论的几种方法组合都具有高灵敏度、快速、准确度高、线性范围宽等优点,可满足茶叶中农药检测的要求。