毛细管气相色谱法测定牛奶中有机氯和有机磷农药残留量

采用一个较快速、简单的方法测定牛血中有机氯和有机磷农药残留物。牛奶中农残经氯仿萃取和固相提取净化后，分别用气相色谱－电子捕获检测器和气相色谱－火焰光度检测器直接测定，色谱柱为ＨＰ－１接ＨＰ－５、ＤＢ１７大口径石英毛细管柱。本法对１７种有机氯农残的回收效率范围为７１．２％￣９９．７％，检测限为０．５￣９μｇ／ｋｇ。而１１种有机磷农残的回收率范围为７０．１％￣９６．１％，检测限则为０．０１￣０．０４ｍ     

土壤中绿黄隆残留量分析方法的研究

本文确立了土壤中绿黄隆残留量的间接气相色谱分析方法，用０．１５ｍｏｌ／Ｌ ＮａＨＣＯ３提取土样，二氯甲烷洗涤初步纯化后，在水浴上加热水解，再用二氯甲烷萃取，弗罗里硅土柱净化，最后用气相色谱－电子捕获检测器检测水解产物邻氯苯磺酰胺。土壤中添加回收率７８．５％－９０．８％，检测极限０．３ｎｇ／ｇ。     

快速气相色谱法测定蔬菜中甲胺磷和水胺硫磷残留量

蔬菜中甲胺磷和水胺磷残余经氯仿萃取后，用气相色谱－火焰光度检测器（ＧＣ－ＦＰＤ）直接测定，色谱柱为ＤＢ－１７大口径石英毛细管柱，采用气相色谱－离子阱质谱系统检测样品中的甲胺磷和水胺硫磷，在三个不同含量水平的收率试验中，本法的回收率为９３．６％－１０４．１％，最低检测限可达０．０６μｇ／ｇ     

固相萃取–气相色谱法测定甘草中的六六六、滴滴涕含量

建立了甘草中六六六、滴滴涕农药残留量的固相萃取–气相色谱–ECD测定方法。甘草样品用水浸泡后加入乙腈,以超声辅助振荡提取,采用Florisil固相萃取柱净化,经DB–1毛细管柱(30 m×0.25 mm,0.25μm)分析,进样口温度为220℃,电子捕获检测器温度为320℃。六六六、滴滴涕农药的质量浓度在0.005~0.5μg/m L范围内线性良好,相关系数为0.990 0~0.999 5。在0.05,0.1,0.5 mg/kg 3个添加水平下,2种农药共8个异构体加标回收率为60.1%~122.2%,相对标准偏差为2.3%~15.1%(n=5),检出限为0.25~1.4μg/kg,定量下限为0.56~3.06μg/kg。该方法具有样品前处理操作简单、灵敏度高、试剂用量少、选择性高、重现性好等优点,适用于甘草中六六六、滴滴涕农药残留量的快速测定。     

QuEChERS Technique for the Gas Chromatographic Determination of Organophosphate Residues in Strawberries

This study describes the validation of an analytical method employing gas chromatography with flame photometric detection for the determination of organophosphate pesticides (diazinon, disulfoton, parathion, chlorpyrifos, and malathion) in strawberries. The method employed a QuEChERS dispersive solid phase extraction for the sample preparation. QuEchERS is inexpensive, fast, and easy for the separation of the analytes from the matrix. In addition, the method provided linear calibration curves, ranging from 0.10–1.00 µg g^?1, for diazinon, disulfoton, parathion, and chlorpyrifos, and 0.10–2.00 µg g^?1 for malathion. Recovery studies yielded values in the range from 81.64 to 100.00%. These results demonstrated the potential of the technique for the determination of organophosphate residues in strawberries.     

Gas Liquid Chromatographic Determination of Caffeine in Breast Milk and Blood Plasma

Abstract

An improved procedure for the determination of caffeine in the presence of bupivicaine (internal standard) using gas liquid chromatography with nitrogen phosphorous detection is described. The method is based on the extraction of caffeine from plasma with a mixture of chloroform and isopropanol (95:5). The chloroform and isopropanol mixture is evaporated to dryness and the residue dissolved in 500 μl of ethyl acetate. One to 2 μl samples are injected directly into the gas chromatograph. This extraction process doesn't give rise to troublesome interfering peaks in the chromatogram. The recovery of caffeine from plasma and breast milk is approximately 99.7% and 94.1% respectively. The coefficient variation of the assay from plasma and breast milk is 2.90% and 1.18% respectively. The limit of quantitation is 0.05 mcg/ml of plasma or breast milk. Data are presented to illustrate the practicality of the method for bioavailability and pharmacokinetic evaluation of caffeine plasma and breast milk levels after oral administration of 100 mg of caffeine to lactating mothers.     

长链烷基苯异构体的气相色谱研究

长链烷基苯异构体的分离分析是石油化学中一个重要课题,曾有较多作者用气相色谱方法研究了长链烷基苯的分离及不同碳数的     

快速气相色谱法测定蔬菜中菊酯类农药残留量

采用一种较快速，简单的方法测定蔬菜中菊酯类农药残留物。样本中农残经乙酸酯萃取，凝胶渗透色谱及固相提取净化后，用气相色谱－电子捕获检测器测定，色谱柱为ＨＰ－５小口长石英毛细管柱。本法对６种常用菊酯类农药的回收率范围为８９．６％－９９．７％，检测限为０．０４ｍｇ／ｋｇ。对同一批普施用菊酯类农药的白菜样本进行化验，本法跟美国食物及药品管理局农药残留标准测定方法所得结果非常吻合。     

毛细管气相色谱法测定水体及土壤中溴氟菊酯农药的残留量

建立了新品农药溴氟菊酯在水体及土壤中残留量的测定方法，采用石油醚＋丙酮（３＋１）混合溶剂提取，经浓硫酸＋无水乙醇（１＋１）纯化，用毛细管气相色谱电子捕获检测器测定。该法检出限为０．１×１０－９～２×１０－９，回收率７２．６％～１００．５％，变异系数１．６％～８．５％。     

固相萃取/毛细管气相色谱法测定肉桂皮中六六六、滴滴涕农药残留量

研究了肉桂皮中六六六、滴滴涕农药残留量的测定方法。以丙酮-石油醚混合溶剂为提取剂,旋涡振荡提取,采用固相萃取技术对提取液净化,优化洗脱溶剂的比例和用量,用气相色谱/微电子捕获检测器（μECD）测定。在优化条件下,BHC及DDT农药在10~1 000 μg/L质量浓度范围内线性关系良好,相关系数为0.995 8~0.998 1。2种农药在肉桂皮中的加标回收率为 92.1%~112%,相对标准偏差（RSD）为2.8%~8.1%,方法的检出限（LODs）为5.0×10-3~2.4×10-2 mg?kg-1,定量下限（LOQs）为1.3×10-2~6.0×10-2 mg?kg-1。方法具有简单、灵敏、选择性高、重现性好等优点。     

新型色谱固定相炭化树脂色谱分离性能的研究

高分子树脂裂解后的余炭骨架,即炭化树脂,具有较优良的色谱分离性能和分离特点.考查了炭化树脂作为色谱固定相的物理特性、吸附特性和表面稳定性.     

气相色谱-负离子化学源质谱法分析牛奶饮品和奶粉中19种有机磷农药残留

将气相色谱-负离子化学源质谱法(GC-NCIMS)应用于牛奶饮品和奶粉中19种有机磷农药残留的同时分析。牛奶饮品和奶粉经乙腈提取剂超声提取、Florisil硅藻土和中性氧化铝双净化剂同时净化及正己烷-乙酸乙酯(体积比1∶1)混合洗脱剂洗脱后,以三苯基磷酸酯为内标物,采用GC-NCI MS的选择离子监测方式(SIM)定性与定量分析。当牛奶饮品和奶粉的加标浓度水平为20、100、500μg/kg时,平均加标回收率为64.5%~129%,相对标准偏差为2%~20%;除喹硫磷的方法检出限(MDL)为2.4μg/kg外,其余18种有机磷农药的MDL均小于1.0μg/kg;线性范围为10~500μg/kg,相关系数均大于0.9988,此分析方法成功地应用于牛奶饮品和奶粉中多种痕量有机磷农药残留的分析。     

荔枝中代森锰锌及其代谢产物乙撑硫脲残留量的气相色谱测定

建立了将代森锰锌分解为二硫化碳、顶空气相色谱法(电子捕获检测器)测定荔枝中代森锰锌残留量及将乙撑硫脲转化为S_乙撑硫脲, 气相色谱法(氮磷检测器)测定荔枝中乙撑硫脲残留量的方法。代森锰锌在0.25~4.00μg含量范围内, 色谱峰高的对数与农药含量平方的对数呈现良好的线性关系, 相关系数为0.999; 荔枝果肉中代森锰锌的回收率为96.0%~103.3%, 相对标准偏差为3.54%~5.51%(n=3), 定量下限为1.0×10-10g。乙撑硫脲线性范围为0.25~5.00μg/mL, 荔枝果肉中乙撑硫脲的回收率为87.3%~105.6%, 相对标准偏差为3.22%~4.63%(n=3), 定量下限为5.0×10-10 g。应用该法测定了实际荔枝样品中代森锰锌与乙撑硫脲的残留量, 并对其进行了安全性分析。     

牛奶中32种农药的气相色谱-离子阱串联质谱法测定

建立了牛奶中有机氯、有机磷和拟除虫菊酯3类32种农药残留的气相色谱-离子阱串联质谱(GC-IT-MS/MS)分析方法。针对目标物灵敏度不同选择电子轰击电离源或化学电离源,系统地优化了串联质谱的分析条件,并分析了产生这些影响的机理。在优化条件下,32种农药在25(10)～500(200)μg/L范围内线性关系良好,相关系数均大于0. 994;倍硫磷和毒死蜱的方法检出限(MDL)分别为1. 7μg/kg和2. 8μg/kg,其它30种农药的MDL为0. 026～1. 2μg/kg;当样品的加标浓度水平为50、200μg/kg(有机氯类农药的加标浓度为20、100μg/kg)时,32种目标物的平均加标回收率为71. 5%～116%,相对标准偏差为1. 9%～14%。将方法应用于实际样品的检测,其抗干扰能力强,能减少分析结果的假阳性。     

微波处理-气相色谱法测定含硫蔬菜中的多类农药残留

建立了含硫蔬菜(洋葱、大蒜、青葱、韭菜等)中有饥磷、有机氯和拟除虫菊酯多类农药残留的简单、快速检测方法。采用家用微波炉处理含疏蔬菜40s,使其中的酶失去活性,避免产生干扰的硫化物,再用乙腈均质提取,PSA固相萃取柱净化,用气相色谱一电子俘获检测器(ECD)及火焰光度检测器(FPD)检测。添加样品的回收率在70％～110％之间,相对标准偏差在3．5％～14．2％之间。     

伏安免疫法检测牛奶中氯霉素残留

为探索用于现场检测牛乳中氯霉素(CAP)残留的高灵敏度及特异性强的免疫传感器方法,本实验在制备CAP单克隆抗体的基础上,以卵清蛋白-氯霉素(OVA-CAP)偶联物为包被抗原,并将其包被到聚苯乙烯反应板上;在孵育反应中,样品中的CAP与OVA-CAP竞争结合CAP单克隆抗体,洗涤后加入碱性磷酸酶(ALP)标记的二抗,经再次孵育及洗涤后加入对硝基苯磷酸(pNPP)底物液;反应终止后用线性导数伏安法记录pNPP水解产物的氧化峰电流。实验结果表明,用免疫传感法测试CAP的灵敏度高于传统的间接竞争酶联免疫吸附法(ELISA)。该方法检测CAP的检出限为0.064μg/L;检测线性范围为0.15~600μg/L,测试牛奶样品的平均回收率为89.8%。另外,由于免疫电化学传感器体积较小,便于携带,操作简单,可实现牛乳样品中CAP残留的现场检测。     

High-Performance Thin-Layer Chromatographic Determination of Carbamate Residues in Vegetables

JPC – Journal of Planar Chromatography – Modern TLC - A high-performance thin-layer chromatographic method has been developed for determination of four carbamate residues in vegetables....     

用低温气相色谱分析火焰气体

本文采用低温气相色谱法分析了火焰气体的成份和深度，色谱柱固定相为ＰｏｒａｐａｒｋＱ，柱温范围－９９－２５０℃氦气作载气。在所选择的实验条件下，火焰气体中的Ｎ２和Ｏ２有效地得到分离，可迅速精确地分析确定Ｎ２的浓度以及其他成份和浓度。     

Study on the Performance of Three Different Capillary Gas Chromatographic Analyses in the Evaluation of Milk Fat Purity

The adulteration of milk fat with foreign fat has been and still is a major concern in the dairy industry. Milk fat purity is currently evaluated by triglyceride analysis by using the Official EU method. The detection limit of the various vegetable and animal fats ranges between 4 and 6%. This research was carried out to verify whether it is possible to decrease the detection limits of beef tallow, which is the most widely used adulterating animal fat. For this purpose, determinations of diglycerides and 3,5-cholestadiene, together with the Official EU method, were applied both to several samples of pure milk fat and to mixtures of milk fat with different percentages of beef tallow. The best results were obtained combining the data deriving from the three determinations by multivariate statistical techniques; in particular, the statistical model obtained by the UNEQ technique seems to be able to decrease the detection limit of beef tallow from 5.2 to 2%. The diglyceride and 3,5-cholestadiene evaluation, combined with the Official EU method for triglycerides, can be usefully applied both to detect small additions of beef tallow and to demonstrate the adulteration of milk fat samples showing results close to the detection limit of the official method.