共查询到20条相似文献，搜索用时 46 毫秒
1.
A capillary column gas chromatographic method is described for the determination of tau-fluvalinate in honey samples. The method involves solid phase extraction of the sample with two RP C-8 cartridges in series, purification of the extract, if necessary, on a silica cartridge, and detection of the active ingredient with an electron capture detector. The method is rapid and overcomes the problem of emulsion formation in liquid/liquid partition often found in traditional systems. The detection limit in actual samples is 0.01 mg kg?1 and mean recoveries for fortified samples prepared with or without clean-up are greater than 85%. 相似文献
2.
Kevin N. T. Norman 《Pest management science》1991,33(1):23-34
An automated gas chromatographic headspace method capable of detecting halogenated compounds in cereals, nuts and seeds at levels down to μg kg?1 or less has been developed and evaluated. Commodities were analysed directly without extraction or clean-up and a simple calibration technique offers a rapid screening quantitative analytical method. Comparison of results obtained using an established solvent extraction method with those obtained using the method described showed good quantitative agreement. Minimum detectable quantities were lower using the headspace method for every fumigant residue/commodity studied. The recommended analytical conditions are suitable for examination of further commodities for the fumigant residues examined and for other volatile halocarbons. 相似文献
3.
Kevin N. T. Norman Keith A. Scudamore Wendy A. Matthews Michael F. Wilson 《Pest management science》1995,44(4):309-316
An automated gas chromatographic headspace method capable of detecting methyl bromide (MB) down to 0.01 mg kg?1 has been developed and evaluated. The method is suitable for analysing cereals, nuts, seeds and dried fruit. Commodities are extracted with solvent and MB present is derivatised to methyl iodide (MI) which is determined by automated headspace gas chromatography. Results from the method described are compared with those using an established solvent extraction method and show good quantitative agreement. The analytical conditions recommended are likely to be suitable for examination of other commodities for MB residues. 相似文献
4.
A gas chromatographic method to determine flumethrin (‘Bayvarol’) in honey samples is described. The method consists of solid-phase extraction with RP C-18 cartridges, clean-up if required on silica cartridges, and quantitation of the active ingredient with an electron capture detector using deltamethrin as internal standard. Compared to previous methods it is very rapid, and a number of samples can be prepared simultaneously. The minimum detectable quantity is 0·005 mg kg?1 and mean recoveries are of the order of 95%. 相似文献
5.
6.
Allan J. Cessna 《Pest management science》1990,30(2):141-147
A gas chromatographic method, using electrolytic conductivity detection, is presented for the determination of 2,4-0 as its methyl ester in triticale (X Triticosecale Wittmack). The method was used to monitor the dissipation of 2,4-0 residues in triticale over a growing season at two sites following post-emergence application of the dimethylamine salt of 2,4-D at 0.56 kkg ha?1. Initial residues, in the order of30 mg kg?1. on the day afer application (3- to 4-leaf stage of the crop), decreased to non-detectable levels in the mature straw and seed. Recoveries of 2,4-D were greater than 90% fiom green tissue fortified at 0.1 mg k?1., and in the order of 75% from seed fortified at 0.05 mg kg?1. 相似文献
7.
建立了简单、灵敏的土壤及苹果中草甘膦残留量的气相色谱检测方法。土壤样品用2 mol/L 的氨水提取,经三氟乙酸酐(TFAA)和三氟乙醇(TFE)衍生化后,由配有氮磷检测器的气 相色谱(GC-NPD)进行检测。土壤中草甘膦的最小检出量为9×10-12 g,最低检出浓度为0.02 mg/kg, 平均回收率及变异系数分别为84.4% ~94.0% 和7.46% ~10.40%。苹果样品则采用去离子水提取,经二氯甲烷液液分配和BIO-RAD AG 50W-X8阳离子交换柱净化后,再用TEAA和TFE衍生化,最后用GC-NPD检测,其中草甘膦的最小检出量(LOD)和最低检出浓度(LOQ)与土壤样品中的相同,平均回收率及变异系数分别为80.7% ~98.6%和9.3% ~11.8%。草甘膦的衍生化产物通过气相色谱-质谱联用仪(GC-MS)进行了确证。在北京昌平地区进行的消解动态和最终残留试验结果表明,以推荐高剂量(有效浓度)的1.5倍(2 025 g/hm2)施药,草甘膦在土壤中的半衰期为 9.2 d。两年的最终残留试验结果表明,无论是高浓度区(2 025 g/hm2)还是低浓度区(1 350 g/hm2),苹果收获时(距施药75 d),土壤和苹果样品中均未检出草甘膦。 相似文献
8.
建立了检测含油类食品(核桃、花生油和干辣椒粉)中亚胺唑残留的分散固相萃取-气相色谱分析方法。样品中的亚胺唑经乙腈提取,N-丙基乙二胺吸附剂(PSA)和十八烷基键合硅胶吸附剂(C18)混合分散固相萃取净化剂净化,气相色谱法测定,基质标准曲线-外标法定量。结果显示:在0.005~10 mg/L范围内,亚胺唑的色谱峰面积与其质量浓度间呈良好的线性关系,相关系数r > 0.99;定量限为0.05 mg/kg。在0.05、0.1和1 mg/kg添加水平下,亚胺唑在核桃、花生油及干辣椒粉基质中的添加回收率为82%~107%,相对标准偏差为3.0%~6.3%。方法各项性能均能满足对含油食品中亚胺唑残留分析的要求。 相似文献
9.
An analytical procedure to detect N-(3-ethylsulfonyl-2-pyridinyl)-4,6-dimethoxy-2-pyridineamine, a degradation product deriving from the hydrolysis of rimsulfuron in soil, has been developed. The analytical standard was prepared by basic hydrolysis of rimsulfuron at pH 9 and purification on a silica gel chromatographic column. The compound obtained was stable at high temperature, thus enabling determination by gas chromatographic analysis. Soil samples were extracted with acetonitrile, purified with a SPE C18 cartridge and analysed using both nitrogen phosphorus (NPD) and mass spectrometer detectors. The analytical procedure described proved to be sensitive and reproducible. Recoveries varied from 84 to 90%. The limit of sensitivity was 0·001 mg kg-1. © 1997 SCI. 相似文献
10.
人参中18种有机氯农药多残留分析方法 总被引：1，自引：0，他引：1
建立了人参中18种有机氯农药及其异构体残留量的气相色谱分析方法。样品以30mL石油醚-丙酮(1∶ 1,体积比)为提取剂,冰浴超声提取15 min,重复2次,提取液用浓硫酸净化,采用HP-5与DB1701毛细管色谱柱双柱定性分离,气相色谱-电子捕获检测器(GC-ECD)测定。结果表明:该方法在10、50、100 μ g/kg 3个水平下的添加回收率除艾氏剂与苯氟磺胺在62%左右外,其余 分别在75.1%~107.7%、72.1%~98.6%和71.5%~105.4%,相对标准偏差(RSD)分别为2.5%~ 11.3%、2.6%~12.5%和1.1%~11.2%;方法的检出限为3.14 μ g/kg,定量限为10 μ g/kg。 相似文献
11.
A method is described for the analysis of water, soil and crops for residues of the herbicide butachlor. Residues were extracted with acetone + light petroleum distillate. The extracts were concentrated and purified on a chromatographic column containing aluminum oxide, silver–aluminum oxide and Florisil. Finally, they were quantitated by gas chromatography using an electron-capture detector. The detection limits of various samples were between 0.001 and 0.015 mg kg?1. The average recoveries ranged from 79.4 to 104.6%. 相似文献
12.
Mario Businelli Francesco Tafuri Cesare Marucchini Luciano Scarponi 《Pest management science》1975,6(1):69-73
A gas-liquid chromatographic method using electron-capture detection is described for the determination of perfluidone residues in rice grains and husks. The procedure consists of extraction, purification on an anion-exchange resin, methylation and further clean-up (if necessary) by adsorption on “Florisil”. The recoveries from fortified rice grains and husks were respectively 73.5–98% and 77–104% in the range 0.01–0.50 mg/kg. Sensitivity permits detection of perfluidone at 0.005 mg/kg level. 相似文献
13.
A normal-phase high-performance liquid chromatographic method is described for the determination of carbendazim in wine, cereals and fruits. Residues are extracted from samples with methanol. Preliminary liquid partitioning into hexane may be necessary, according to the crops, followed by liquid partitioning from aqueous solution into dichloromethane. Purification is performed by silica-column chromatography or with a silica solid-phase extraction cartridge. Determination and quantification are made by HPLC using an aminobonded stationary phase with fluorescent detection at 285/315 nm. Recoveries range from 80 to 95% for various fortification levels. The method provides a minimum detectable amount below 0.1 ng and quantification limits for various samples are between 0.01 mg kg-1 and 0.1 mg kg-1. 相似文献
14.
A flow injection spectrophotometric method for the determination of carbofuran in commercial pesticide formulations was developed. The determination involves on‐line hydrolysis of the extracted carbofuran at room temperature with sodium hydroxide. The resulting carbofuran‐phenol is coupled with diazotized 4‐aminobenzoic acid in order to achieve an appropriate selectivity and sensitivity for the spectrophotometric measurements. The calibration curve is linear over the range 1–10 mg litre−1 of carbofuran. The proposed method has a detection limit of 0.15 mg litre−1 of carbofuran and a sample frequency of 120 injections per hour. The relative standard deviation of six independent determinations of a sample containing 1 mg litre−1 carbofuran was 0.6%. The suitability of the proposed procedure for the determination of carbofuran in commercial pesticide formulations was studied. The procedure provides results comparable to those obtained by liquid chromatographic analysis. © 2000 Society of Chemical Industry 相似文献
15.
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
16.
本文采用气相色谱法,以外标法定量检测毒死蜱中微量甲苯的含量,其方法的标准偏差为0.13;变异系数为0.16%;线性相关系数为0.9999;平均回收率为100.4%。 相似文献
17.
A gas chromatographic residue method for use on animal tissues, fat, and milk is presented for the organophosphorus insecticide iodofenphos. The procedure includes the determination of two potential metabolites, iodofenoxon, and 2,5-dichloro-4-iodophenol. The two phosphorus-containing compounds are analysed by means of a flame photometric detector after cleanup including silica gel column and thin-layer chromatography. The substituted phenol is determined separately as the acetylated derivative using an electron capture detector. Some information on the problem of specificity with regard to possible interferences by closely related insecticides or their corresponding phenols is also given. 相似文献
18.
Kenneth K. H. Fung 《Pest management science》1976,7(6):571-574
Gas chromatographic methods for the determination of methomyl residues in soil and water utilising the flame photometric detector are described. Complete extraction of methomyl residues in soil and water was obtained and the analytica.1 results were reproducible. Recovery of 90–96 % of methomyl residues was possible based on 50 g of soil and 1 litre of water. The identity of methomyl residues determined was confirmed by gas chromatography-mass spectrometry. 相似文献
19.
Hughes EA Zalts A Ojeda JJ Flores AP Glass RC Montserrat JM 《Pest management science》2006,62(9):811-818
An analytical method has been developed that can be used to determine the potential dermal exposure (PDE) of workers to the pesticide captan in small-scale horticultural production units. The methodology is based on the whole body dosimetry technique, using a cotton coverall and cotton gloves as sampling media, with protective clothing worn beneath the cotton media to protect the operator. The quantitative determination of captan was done by gas chromatography-electron capture detector (GC-ECD), with the analytical method validated by measuring limits of detection and quantification, linear ranges, sample recovery and precision. Special emphasis is placed on factors that affected the stability of captan during chromatographic determination. The data generated for potential dermal exposure are presented separately for mixing/loading and application activities. These data are compared with values obtained with visible tracers using a similar field technique. Margin of safety (MOS) values are also calculated for the agricultural procedures studied. 相似文献
20.
I. H. Williams 《Pest management science》1972,3(2):179-181
A microcoulometric method is described for the direct determination of nanogram amounts of methomyl (S-methyl-N-[(methylcarbamoyl)-oxy]thioacetimidate). An all-glass gas chromatographic system coupled to a microcoulometer with a nitrogen-specific cell was used. The column was packed with a mixture of 6% OV210 and 4% OV101 on Gas Chrom Q, as was the glass transfer tube which connected the chromatographic column to the pyrolysis furnace. Some loss occurred but response was linear from 125 to 20 ng and sensitivity was such that 20 ng of methomyl could be readily measured. 相似文献