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1.
Soxhlet extraction with hexane + acetone (1 + 1 by volume) was used for the extraction of organochlorine pesticide residues from river sediments, followed by Florisil column chromatography clean-up and determination by gas chromatography with an electron-capture detector. Average recoveries exceeding 90 % were obtained using this technique. Organochlorine pesticide residue levels in sediment samples from two major rivers flowing through predominantly rice-growing areas were determined by this method. Relatively high residue levels of organochlorine pesticides such as HCH, heptachlor and endosulfan were found in the sediments.  相似文献   

2.
A multiresidue analytical method for the simultaneous extraction of organochlorine, organophosphorus, dinitrophenyl and carbamate pesticides from apples is presented. Extraction is performed with a mixture of toluene and hexane. After clean-up on a Florisil column, and in some cases conversion to derivatives, quantitative determination is performed by electron-capture gas chromatography. Qualitative verification is performed by thin-layer chromatography or gas chromatography-mass spectrometry.  相似文献   

3.
Antibody molecules were produced by injection of BSA-Kelevan into chickens and rabbits. Pure antibody was obtained by a single pass of blood serum through an affinity column. The affinity gel was prepared by covalently binding BGG-Kelevan to activated Sepharose 4B-CN. Purity of the antibody was determined by ultracentrifugation and gel electrophoresis. Properties of the antibody included: sedimentation coefficient = 6.2, pI = 7.0, calculated MW = 150,000, and precipitin band formation using the microouchterlony test. The antibodies in free or immobilized form were able to prevent or reverse Kepone inhibition of ATPase activity from a variety of tissues from different sources. About 70 μg (approx 0.4 μM) of purified antibody was sufficient to restore the activity of mitochondrial (oligomycin-sensitive) Mg2+ ATPase activity which had been inhibited (in vitro) by 1 μM Kepone. The antibody was effective in preventing enzyme inhibition by other organochlorine pesticides with widely differing molecular structures. However, nonchlorinated inhibitors of mitochondrial oligomycin-sensitive Mg2+ ATPase activity were much less affected by the antibody. The available evidence suggests that the antibody binding site for the hapten may be specific for secondary or induced bonding forces due to the carbon-chlorine bonds rather than for a specific molecular structure.  相似文献   

4.
A liquid chromatography multi-residue method with photometric detection has been developed. The method is applicable to the quantitative determination of organochlorine (tetradifon, dicofol, chlorfenson, chlorobenzilate), organophosphorus (fenitrothion, azinphos-ethyl) and carbamate (pirimicarb) pesticides in animal tissues. The extracted residues are cleaned up by gel-permeation chromatography. A further fractionation on silica Sep-Pack cartridges is included in the procedure. A gas chromatographic method with electron-capture detection for the analysis of the same pesticides was carried out and the results in the two cases compared. Lower detection and quantitation limits and similar recoveries of pesticides from spiked pig liver and brain samples were obtained by the LC method. © 1997 SCI.  相似文献   

5.
BACKGROUND: Pesticide‐formulating industries are contaminating the environment through various activities. Bioremediation is the best method for decontamination, as chemical and physical methods are not only costly but also not very effective in open field systems. In the present study, in situ bioremediation of organochlorine‐contaminated soil was demonstrated by combined biostimulation and bioaugmentation strategies, followed by evaluation using a molecular method. RESULTS: Three parameters were monitored: microbial biomass (colony‐forming units (CFU) g?1 soil), residual pesticides after treatment and catabolic genes from microcosm soil. Both the biostimulation and the bioaugmentation treatments showed an initial lag phase of 80 days towards colony‐forming units. Gas chromatography of soil samples showed that concentrations of residual pesticides in the soil declined by up to 85–90% after 80 days, indicating their utilisation with time. On dot‐blot hybridisation of the total DNA from the same soil samples, it was observed that catabolic genes tfdC (catechol 1,2‐dioxygenase) and cm genes (chlorophenol monoxygenase) were predominant, whereas other catabolic genes such as catechol 2,3‐dioxygenase (xylE) were negligible. CONCLUSION: The strategy of in situ bioremediation and its evaluation by gene probe and also by conventional methods was demonstrated for organochlorine‐pesticide‐contaminated soil in open microcosms. It showed that bioaugmentation along with biostimulation was effective, although initial acclimatisation for a period of almost 2–3 months was required in the open field systems. Copyright © 2009 Society of Chemical Industry  相似文献   

6.
建立了一种高效、选择性强的分子印迹-基质固相分散萃取结合高效液相色谱测定土壤中4种硫代磷酸酯类农药(毒死蜱、甲基立枯磷、甲基毒死蜱、甲基对硫磷)残留量的方法;并以甲基立枯磷为模板分子,以甲基丙烯酸(MAA)为功能单体,且n(模板分子)∶n(功能单体)=1∶4,以乙二醇二甲基丙烯酸酯(EDMA)为交联剂,以偶氮二异丁腈为引发剂,采用沉淀印迹聚合方法,合成了甲基立枯磷高分子印迹聚合微球(MIPs);以MIPs作为土壤样品提取液的基质固相分散吸附剂,采用HPLC检测处理后的样品,流动相为V(乙睛)∶V(0.1%乙酸水溶液)=3∶1,流速0.8 m L/min,进样量20μL,检测波长210 nm,采用Agilent Eclipse XDB-C8色谱柱(150 mm×4.6 mm,5μm),柱温25℃。结果显示:MIPs对甲基立枯磷有特异性吸附,对其结构相似物毒死蜱、甲基对硫磷和甲基毒死蜱也具有一定的吸附性能;在0.01~5.0 mg/kg范围内,各药剂的质量浓度与相应的峰面积间呈良好的线性关系,相关系数r为0.997 5~0.999 8;4种硫代磷酸酯类有机磷杀虫剂的检出限(LOD)为0.452~1.226μg/kg;添加回收率为76%~96%,相对标准偏差(RSD)为2.8%~7.3%。该方法可用于土壤中硫代磷酸酯类有机磷杀虫剂残留量的测定。  相似文献   

7.
宋淑玲  饶竹 《农药学学报》2011,13(5):439-447
在查阅大量相关文献并结合作者自身研究工作经验的基础上,根据介质中干扰物的种类和特点,按照不同介质进行分类,重点介绍了填充柱、固相萃取、凝胶色谱、磺化和基质固相分散等净化技术在检测分析水、土壤、沉积物、茶叶、中药以及脂肪性样本中有机氯农药残留中的应用。认为将净化技术与提取技术或分析技术有效结合,提高样品净化效率及整体分析速度将是未来净化技术的主要发展趋势。  相似文献   

8.
A total diet, representative of a Canadian's daily food intake was formulated, grouped by types of food, and prepared as for eating. Analysis of these composites for residues showed eleven organochlorine but no organophosphorus pesticides. Residues were low and would yield an average total daily intake of 24μg/person/day. The level of arsenic was determined on one-quarter of the samples and was found to be consistently below 0.1 ppm.  相似文献   

9.
以人参为原料,研究了利用高效的亚临界丙烷萃取技术脱除人参提取物中残留的有机氯农药的可行性。就萃取压力、萃取温度、萃取时间和溶剂流量等对萃取效果的影响进行了比较,并用高压液相色谱仪测定了脱除农药前后人参皂甙的含量。结果表明,在萃取压力为8 MPa、65℃下萃取120 min,溶剂流量为2.94 kg/h的条件下,可几乎完全脱除γ-HCH,op-DDT,对TCNB、pp-DDT、DDE脱除率大于60%,人参皂甙损失小于6.53%。此方法为脱除人参中残留的有机氯农药提供了有效的途径。  相似文献   

10.
Reversed-phase high-pressure liquid chromatography (h. p. l. c.) and thin-layer chromatography (t. l. c.), on commercially available, reversed stationary phases, were used to determine the octan-1-ol/water partition coefficients (P) for 20 non-ionic organic chemicals, consisting mainly of known pesticides in common use. Good correlation was found between log P values and both the logarithms of the capacity factor (k′), obtained by h. p. l. c., and the Rm values derived from t. l. c. The methods were found to be applicable over a range of more than six orders of magnitude in P values. In addition, the relation is shown between the P values of organic chemicals and their solubilities in water and in octan-1-01.  相似文献   

11.
采用推杆式滤过型净化柱净化,结合超高效液相色谱-三重四极杆/复合线性离子阱质谱仪(UPLC-QTRAP-MS/MS)建立了草鱼样品中11种农药残留的检测方法。以乙腈为提取剂,样品经超声、冷冻、离心后,上清液采用以50 mg PSA为净化填料的推杆式滤过型净化柱进行1次快速净化;超高效液相色谱快速分离,三重四极杆/复合线性离子阱质谱仪进行测定。基质匹配法制作标准曲线,外标法定量。结果表明：11种农药在1.0～50.0μg/kg内的线性关系良好,相关系数均大于0.99;定量限为1.0～2.0μg/kg。不同添加水平下的回收率为83%～119%,日内相对标准偏差为2.6%～20%,日间相对标准偏差为0.7%～15%。该方法经济、简便、高效,灵敏度高,重复性好,可作为草鱼中农药残留的日常检测方法。  相似文献   

12.
采用气相色谱法建立了水果中氟吡菌酰胺、肟菌酯及其代谢物肟菌酸残留的分析方法。样品用乙腈匀浆提取,氯化钠和无水硫酸镁盐析后,经N-丙基乙二胺（PSA）分散固相萃取净化,气相色谱-电子捕获检测器（GC-ECD）检测。结果表明:在0.05~1 mg/kg添加水平下,氟吡菌酰胺、肟菌酯及其代谢物肟菌酸的平均回收率为79%~120%,相对标准偏差（RSD）为0.7%~16%。氟吡菌酰胺、肟菌酯及其代谢物肟菌酸在不同水果样品中的检出限（LOD）分别为0.01、0.015和0.01 mg/kg,定量限（LOQ）均为0.05 mg/kg。该方法快速、简单和稳定,可以满足水果中氟吡菌酰胺、肟菌酯及其代谢物肟菌酸残留量的检测要求。  相似文献   

13.
建立了应用高效液相色谱分别测定炔草酯及其代谢物炔草酸在小麦和土壤中残留量的方法。样品经乙酸乙酯或丙酮提取,中性氧化铝柱层析净化,高效液相色谱法测定。结果表明:炔草酯在小麦籽粒、植株和土壤中的平均回收率为80.4%~92.5%,相对标准偏差(RSD)为1.5%~4.4%;炔草酸的平均回收率为71.7%~83.8%,RSD为2.3%~6.0%;炔草酯和炔草酸的最小检出量分别为1.0×10-9和2.0×10-10 g;在籽粒、植株和土壤中炔草酯和炔草酸的最低检测浓度分别为0.02、0.05、0.02 mg/kg和0.01、0.02、0.01 mg/kg。  相似文献   

14.
Soil samples from five metropolitan areas including Baltimore, Maryland; Gadsden, Alabama; Hartford, Connecticut; Macon, Georgia; and Newport News, Virginia were analyzed for elemental arsenic, organochlorine pesticides, and polychlorinated biphenyls (PCBs). A representative number of samples were analyzed for organophosphorus pesticides, but none was detected. All areas exhibited heavy soil concentrations of organochlorine pesticides including sigma DDT, aldrin, dieldrin, photodieldrin, chlordane, heptachlor, heptachlor epoxide, endrin, endrin ketone, and endosulfan sulfate. PCBs were detected in three of the five metropolitan areas. Within the metropolitan areas, samples from the urban, or core city, locations generally had higher pesticide concentrations than did samples from suburban locations. Finally, pesticide residue concentrations were generally higher in soils of metropolitan areas than in nearby agricultural soils.  相似文献   

15.
A novel method was developed for the simultaneous determination of diquat and paraquat residues in potatoes. Potato tissues were spiked at several levels and extracted with acid using a micro-reflux procedure with 5 g of sample; this was followed by adjusting the hydrolyzate pH to 9 to 10 and using a silica Sep-Pak for rapid clean-up and preconcentration. Aliquots of the final eluate were taken to dryness, dissolved in the h.p.l.c. mobile phase and analyzed as their heptanesulfonate ion-pairs by u.v.-h.p.l.c. (reverse phase column chromatography) at 254 and 313 nm for paraquat and diquat, respectively. A detection limit of approximately 0.05 mg kg?1 dication in a 5-g sample of spiked potato (i.e. 0.25 μg ml?1 final extract) was achieved. Recoveries of 79.5 to 97.6% were obtained at spiking levels of 0.05 to 5.0 mg kg?1 for diquat and paraquat with coefficients of variation not greater than 8.27%. The method was developed and validated using 14C-radiolabelled diquat and paraquat; u.v.-h.p.l.c. recoveries were comparable with recoveries determined by radioassay. Several parameters affecting the extraction, adsorption and chromatography of diquat and paraquat were evaluated. The formula weights of diquat and paraquat were determined and their importance described; they were determined as mono- and tetra-hydrates, respectively.  相似文献   

16.
Recent advances in methodology and instrumentation have made possible the detection and determination of pesticides at microgram kg-1 (ppb) levels. The sensitivity of a method of analysis depends greatly on the efficient extraction of the pesticide and the subsequent clean-up of the extract. The extract from green tea leaves is a mixture of aroma components, polyphenols and caffeine. The preparation of made tea from green tea leaves adds to this complexity by concentrating these coextractives. Conventional clean-up techniques provide poor recoveries for parathion-methyl and chlorpyrifos from both green tea leaves and made tea. This arises from interference by caffeine during gas chromatography, as it has a similar retention time to the two pesticides and peaks overlap. A modification to the protocol based on a solvent partitioning process using dichloromethane and subsequent washing of the extracts with warm water removed the caffeine, and pigments were removed by column chromatography. Recoveries ranging from 80 to 90% were then obtained for both pesticides.  相似文献   

17.
A sensitive method for the detection and estimation of residues of the molluscicide, niclosamide, in bananas is described. The procedure involves extraction of the molluscicide, purification of the extract by solvent partition and column chromatography, formation of the heptafluorobutyryl derivative of 2-chloro-4-nitroaniline in 99% yield and determination of the derivative by gas—liquid chromatography with electron-capture detection. Recoveries from fortified bananas were 89 and 79% at levels of 0.02 and 0.2 mg kg?1, respectively. The sensitivity of the method was such that 0.6 pg of the pure derivative could be detected, based on twice the background noise level on the chromatograph.  相似文献   

18.
An analytical method is presented for the analysis of glyphosate and its metabolite (aminomethyl)phosphonic acid (AMPA), in lentil samples. They were extracted from powdered samples with water and chloroform. The aqueous layer was acidified and passed through a cation exchange column. The eluate was made basic, passed through an anion exchange column in the hydroxide form and discarded. The latter column was eluted with hydrochloric acid (0.3 M) which was collected, evaporated under vacuum to 1 ml, diluted with water to 10 ml, filtered and analysed for glyphosate and metabolite using a liquid chromatograph with a post-column reactor and a fluorescence detector. The limit of detection, average recovery and coefficient of variation (CV) were 0.08 μg g?1, 92.5% and 7.3% for glyphosate and 0.1 μg g?1, 92.5% and 8.3% for AMP A. The detector response was found to be linear within the range 20–400 ng.  相似文献   

19.
应用液相色谱-四级杆飞行时间质谱(LC-QTOF/MS)建立了洋葱中173种农药的快速筛查方法。洋葱样品经含体积分数1%乙酸的乙腈溶液振荡提取,盐析离心,Carbon/NH2净化,在电喷雾全离子二级质谱扫描 (All Ions MS/MS) 正离子模式下采用LC-QTOF/MS进行检测。选择定性筛查时较为重要的离子个数选择模式,色谱共流出曲线相似度匹配得分 (co-elution score) 以及峰高阈值等参数进行了定性筛查方法的优化,最终确定了对采集结果进行分析的最佳筛查参数。同时,应用该方法对洋葱基质中173种农药的定性和定量方法学参数进行了考察。结果表明:167种农药的筛查限和定量限分别在0.001~0.005 mg/kg和0.001~0.01 mg/kg之间,其余6种的筛查限和定量限分别在0.01~0.025 mg/kg和 0.02~0.05 mg/kg之间。所有化合物在测试浓度范围内线性关系良好。添加回收试验 (n=5) 结果显示,在1倍定量限(LOQ)、2倍LOQ和10倍LOQ 3个添加水平下,173种农药中分别有153、168和165种农药的平均回收率在70%~120%之间,相对标准偏差均在20%以内。将本研究建立的筛查方法应用于2020年欧盟组织的水果蔬菜中农药残留检测能力验证 (EUPT-FV22),准确筛查出了组织方在洋葱样品中添加的农药,而且定量结果满意,表明本研究所建立的LC-QTOF/MS筛查方法准确、可靠,适用于洋葱中农药多残留快速筛查和准确定量。  相似文献   

20.
基于改良QuEChERS前处理方法结合气相色谱-串联质谱 (GC-MS/MS),建立了禽蛋中53种农药残留的检测方法。样品用乙酸乙酯提取,经弗罗里硅土和硅藻土净化,用GC-MS/MS分析。采用HP-5MS柱进行分离,电子轰击离子源 (EI) 动态多反应监测模式 (dMRM) 检测,以空白基质匹配标准溶液外标法定量。结果表明:经方法验证,53种农药的仪器检出限 (LOD) 在0.000 25~0.005 mg/L之间,方法定量限 (LOQ) 在0.000 5~0.01 mg/kg之间,相关系数 (r)在0.996 7~1之间;在LOQ、2 LOQ和10 LOQ 3个添加水平下,53种农药在鸡蛋中的平均回收率在76%~104%之间,相对标准偏差在0.090%~14%之间 (n = 6)。该方法前处理快速、检测方法灵敏、准确,在禽蛋中有机氯和有机磷等农药多残留检测中具有较好的应用前景。  相似文献   

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