蔬菜中有机氯农药残留的超临界流体提取和气相色谱法测定

建立了用超临界流体萃取、气相色谱测定韭菜中百菌清、艾氏剂、狄氏剂、异狄氏剂残留量的方法。样品与无水硫酸镁混合后进行萃取。用正交设计法选择萃取条件,最佳条件为压力３０．４ＭＰａ,温度４０℃。静态萃取时间１ｍｉｎ,ＣＯ２用量１５ｍＬ,收集液为乙酸乙酯。     

不同基质中有机氯农药提取技术及发展趋势

该文根据各种基质特点及其中有机氯农药的分布特点,对不同介质中有机氯农药的提取方法进行了归纳.着重介绍了不同基质中有机氯农药提取方法,如均质法、固相萃取法、索氏提取法、基质固相分散法、加速溶剂萃取法、超临界流体提取法、超声波提取法和微波辅助提取法等.通过详细实例,总结了上述提取方法的优缺点,并对有机氯农药提取方法做了展望...     

Supercritical Fluid Extraction of Saponins from Ginseng

Introduction Ginseng（ Panax ginseng C. A. Meyer, Araliaceae） is one of the most valuable Chinese crude drugs and has been used widely for over 2000 years. Studies have demonstrated that ginseng can act on the central nervous system, the cardiovascular system and the endocrine system; it can enhance immune function and metabolism; it possesses a biomodulation action, anticancer effect, anti-stress and anti-ageing activities, and so on.     

固相萃取-GC/MS法测定水样中20种有机氯农药

建立了用固相萃取小柱提取和净化、GC/MS定性定量同时测定水样中20种有机氯农药的方法。方法采用OasisHLB固相萃取小柱萃取富集水样,二氯甲烷洗脱,加入菲-d₁₀作为内标,利用GC/MS进行定性定量,步骤简便,线性响应良好,干扰小,方法检出限为0.21～0.72 ng/L（按水样1L计）,加标回收率为64.8%～122%,RSD为1.2%～11.0 %。成功利用该方法对广西实际河水样品进行了检测。结果表明方法可以同时满足环境水样中20种痕量有机氯农药的测定。     

银杏叶中18种有机氯农药的多残留分析

建立了银杏叶中18种有机氯农药残留量的气相色谱分析方法。对浓硫酸磺化法实验条件进行了优化。样品以丙酮∶石油醚(1∶1)超声提取15 m in,提取液使用含10%H2O浓H2SO4磺化净化,采用DB-1701石英毛细管柱分离样品,GC-ECD测定18种有机氯农药的残留量。此方法3个水平的加样回收率范围为71.6%~130.3%,RSD为2.2%~15.8%。方法快速简便且成本低。     

加速溶剂萃取-凝胶色谱净化-气质联用测定土壤中15种有机氯农药残留的方法研究

建立了加速溶剂萃取-凝胶色谱净化-气质联用同时测定土壤中15种有机氯农药的分析方法。优化了凝胶色谱(GPC)净化的条件,比较了凝胶色谱净化及浓硫酸净化法对15种有机氯回收率的影响。结果表明,采用GPC净化能够有效避免浓硫酸净化对氯丹、异狄氏剂、硫丹、甲氧滴滴涕等农药回收率的影响,GPC净化的最佳收集时间为10~15 min,15种有机氯农药的回收率为56%~122%。15种有机氯农药在0.03~6.0 mg/L范围内具有较好的线性,相关系数达0.999以上,方法的检出限为0.1~5.0μg/kg,定量下限为0.4~16.0μg/kg。采用该方法对实际样品进行加标回收率实验,土壤样品的加标回收率为68%~122%,相对标准偏差为1.2%~5.9%。该方法简单、快捷、灵敏度高,已用于实际土壤样品的检测。     

超临界流体萃取—气相色谱法测定粮谷和茶叶中有机氯农药残留量

介绍了一种用超临界流体萑取进行样品前处理，用吸附小柱进行富集和净化，气相色谱－电子捕获检测器定粮茶叶中１７种有机氯农药残卵留量的方法。对于ＳＦＥ的温度，压力，流速以及吸附小柱的吸附剂类型和用量，洗脱条件等均作了考查。     

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。     

气相色谱法测定黄芪饮片中有机氯类农药残留

采用气相色谱电子捕获检测器(ECD)测定黄芪饮片中9种有机氯类农药残留。黄芪饮片样品以丙酮、二氯甲烷提取,浓硫酸磺化,采用HP–5(30 m×0.32 mm,0.25μm)色谱柱,气化室温度为250℃,检测器温度为300℃。以标准曲线法计算农药含量,加标回收率为94.5%~104.4%,测定结果的相对标准偏差为1.7%~2.7%,检出限为0.061~0.175 ng/m L。该方法简单、快速、稳定、可靠,可用于黄芪饮片中9种有机氯类农药残留的测定。     

Isolation and Extraction of Total Flavonoids from Epimedium Koreanum Nakai by Supercritical Fluid Extraction

In the present paper is reported the metnocl for the isolation and extraction of total flavonoids of Epimedium Koreanum Nateai by means of supercritical fluid extraction(SFE). By examining pressure, temperature, amounts of modifier and extraction time, the optimized condition of SFE is confirmed as 30 MPa and 60℃, with 70% ethanol as the modifier. The samples were statically extracted for 30 min, followed bydynamic extraction for 120 min at a flow rate of 6 mL/min. The quantitative analysis of total flavonoids was performed by UV-Vis spectrophotometry. Compared with the conventional method, the SFE method is more efficient, more rapid and more friendly environmentally.     

Evaluation of Extraction Procedures of Organochlorine Pesticides from Natural Waters and Sediments

Abstract

This study aims to evaluate different procedures for the extraction of organochlorine pesticides (OCP's) from natural waters and sediments. In the case of extraction from water, a C18 disk solid-phase extraction method was employed. Recovery experiments in the range of 40 to 200 ng/l with selected organochlorine compounds resulted in average recoveries between 80 and 100%. Four different solvents, hexane, ethyl acetate, acetonitrile and methanol, were tested as eluting agents. Best recoveries were obtained with ethyl acetate and hexane. A comparative study of OCP sediment extraction procedures was performed employing sonication, Soxhlet extraction and shake-flask methods. The capacity of these methods to recover OCP's from a sediment sample fortified at 50 ng/g was evaluated using hexane : acetone (1:1 v/v), hexane: acetone (8:2 v/v), acetonitrile and dichlorometane. The three extraction techniques gave similar results and dichloromethane was the most effective solvent. The optimised methods were applied in the analysis of waters and sediments from the “Aiguamolls de l'Empordà” Nature Park, Girona (Spain).     

Supercritical Fluid Extraction of Total Flavonoids from Leaves of Acanthopanax Senticosus Harms

Introduction The herbal plant Acanthopanax Senticosus Harms[1,2] is natural herb of Changbaishan in Jilin Province of China, which belongs to the Araliaceae family. As the ingredients of folk medicine, it has long been used to treat a variety of human diseases, such as cerebrovascular disease, diabetes, tumor, isochemic heart diseases, hypertension, rheumatic arthritis,etc.[2,3].     

固相萃取/气相色谱-质谱法对土壤中有机氯农药的分析及基质效应研究

建立了一种固相萃取/气相色谱-质谱法同时测定土壤中23种有机氯农药的方法,并研究了不同基质效应补偿方式。土壤样品经正己烷∶丙酮(体积比1∶1)提取,弗罗里土小柱净化,采用气相色谱-质谱仪检测。结果发现7种有机氯存在中/强程度的基质效应;在10 mL二氯甲烷∶正己烷(体积比1∶9)+10 mL丙酮∶正己烷(体积比1∶9)为固相萃取的洗脱剂,且脉冲压力为275.8 kPa条件下,可将23种有机氯的基质效应均控制在20%以内。23种有机氯农药在0.4～10μg·mL^-1质量浓度范围内线性良好,相关系数(r²)均不小于0.999 2,检出限为1.0～8.6μg·kg^-1,定量下限为4.0～34.4μg·kg^-1;在20、60、100μg·kg^-13个加标水平下空白土壤中的平均回收率为46.3%～127%,相对标准偏差(n=6)为0.68%～15%。采用该方法在某土壤样品中检出α-六六六、γ-六六六、p,p′-DDE、异狄氏剂醛、p,p′-DDT 5种有机氯农药。     

Characterization of Mechanisms of Pesticide Retention in Soils Using the Supercritical Fluid Extraction Technique

Abstract

This research determined the relative effectiveness of supercritical fluid extraction (SFE) in extracting atrazine and its metabolites from soils which had been treated with atrazine for varying periods of time in order to characterize binding mechanisms. Aqueous methanol extraction was more effective than SFE in removing ¹⁴C atrazine residues from “aged” soils. The more polar the solvent system, the more ¹⁴C-atrazine residues were extracted. The order of polarity and extractability was aqueous methanol > SF-CO₂/5% methanol > SF-CO². Atrazine extraction efficiency using SF-CO₂, and SF-CO₂/.5% methanol decreased as samples “aged” in the field. The less than complete recovery of atrazine residues using the SFE technique could be seen as an indication that different binding mechanisms were involved in the retention of atrazine as well as its metabolites and that the binding mechanisms changed with time.     

A Photochemistry Technique Using Ultraviolet Irradiation Followed by Gas-Liquid Chromatography to Confirm the Identity of Some Organochlorine Pesticides

Abstract

A procedure involving ultraviolet (UV) irradiation followed by gas-liquid chromatographic (GLC) detection of photodecomposition products to confirm the identity of selected organochlorine pesticides is described. The Irradiation intensity was standardized by determining the position relative to the UV source which resulted in equal GLC peak heights for the parent compound and major photo-decomposition product after 8 minutes of exposure of a solution of heptachlor epoxide in isooctane. Chromatograms showing photo-decomposition patterns for 33 compounds are presented. Observations and comments on the applicability of this technique to organo-chlorine pesticide residue confirmation are reported.     

苹果中5种氨基甲酸酯类农药的超临界流体萃取及其气相色谱法测定

提出了一种采用超临界流体萃取技术对苹果中５种氨基甲酸酯类农药进行萃取及用气相色谱检测的方法。实验以二氧化碳作为超临界流体，加入３％的甲醇作为改性剂，对３种惰性载体和加入硅藻土的苹果基体的超临界萃取条件进行了选择，以气相色谱配以氮磷检测器检测５种氨基甲酸酯类农药，取得了满意的结果，回收率为８８％～９８％。     

羟基化多壁碳纳米管分散固相萃取/气相色谱-质谱测定茶叶中有机氯农药和拟除虫菊酯类农药残留

建立了羟基化多壁碳纳米管作为吸附剂的改进Qu ECh ERS方法,联合气相色谱-质谱联用法快速检测茶叶中24种有机氯农药和拟除虫菊酯类农药残留量。茶叶样品中的农药残留经正己烷-丙酮(2∶1)提取,以羟基化多壁碳纳米管(MWCNTs-OH)和N-丙基乙二胺键合固相吸附剂(PSA)吸附提取液中的杂质,提取液离心后过滤,经气相色谱-电子轰击源质谱法测定,外标法定量。研究了不同吸附剂种类、提取溶剂、吸附剂用量对提取净化效率的影响。在优化实验条件下,目标物质在0.01~0.50 mg/kg范围内线性关系良好。空白茶叶样品在低、中、高3个加标水平下的平均回收率为78.6%~109.6%,相对标准偏差(n=5)为2.1%~9.3%;方法的定量下限为0.002~0.050 mg/kg。该方法操作简单、快速、灵敏、成本低,能满足茶叶中常见有机氯和拟除虫菊酯类农药残留的检测要求,特别适合在小型实验室和企业中推广使用。     

基质固相分散-加速溶剂萃取-气相色谱法测土壤中有机氯农药残留

建立了用弗罗里硅土作基质固相分散剂的加速溶剂萃取、并以灭蚁灵（Mirex）为内标的快速、同时测定土壤中16种有机氯农药的气相色谱法。加速溶剂萃取仪在100℃,10．3Mpa用正己烷和丙酮（1：1,V／V）静态提取样品10min,0．01μg/g加标水平回收率为77．3％-101．3％;方法检出限为0．01—0．04ng／g。方法满足了土壤中有机氯农药残留测定的要求。对我国南方不同地域的72个土壤样品进行了测定,大部分有机氯农药在土壤中都有一定检出量,其中环氧七氯最高（2．6～844．5ng／g）,甲氧DDT（23．2—219．8ng／g）和P,P’-DDT（4．0—183．1ng／g）次之,而o,P＇-DDT在72个土样中都没有检出。     

微波辅助萃取-固相微萃取-气相色谱法同时测定茶叶中的有机氯和拟除虫菊酯农药残留

建立了微波辅助萃取-固相微萃取-气相色谱(MAE-SPME-GC)同时测定茶叶中六六六(α-BHC,β-BHC,γ-BHC,δ-BHC 4种异构体)、滴滴涕类(DDD,DDE,o,p′-DDT,p,p′-DDT)、氯氰菊酯(cypermethrin)和氰戊菊酯(fenvalerate)等10种农药残留的方法。采用外标法定量,除氰戊菊酯外,农药的质量浓度与其色谱峰面积在一定范围内有较好的线性关系,相关系数为0.9705～0.9984。10种组分的加标回收率为64%～121%,相对标准偏差为10.4%～22.9%,检测限为1～50 ng/L。应用该方法测定了市场上3种茶叶中上述农药残留的含量。     

Supercritical Fluid Extraction Acanthopanax of Total Flavonoids from Leaves of Senticosus Harms

The herbal plant Acanthopanax Senticosus Harms is natural herb of Changbaishan in Jilin Province of China, which belongs to the Araliaceae family. As the ingredients of folk medicine, it has long been used to treat a variety of human diseases, such as cerebrovascular disease, diabetes, tumor, isochemic heart diseases, hypertension, rheumatic arthritis, etc. E2,33. Flavonoids, a class of constituent compounds, which have a broad distribution in the nature and are found in Acanthopanax Senticosus Harms, have gained particular attention. A number of studies have shown that flavonoid compounds have wide biological activities, such as anti-aging, anticancer, anti-HIV,