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101.
Summary A computer-assisted method is described for optimization of multi-component, mobile phase selection for separating enantiomers of four pesticides in normal-phase HPLC. The method is based on the triangle, solvent-selection concept using a statistical scanning method. The optimization of the separation over the experimental region is based on a special polynomial estimation from seven experimental runs, and resolution (Rs) is used as the selection criterion. Excellent agreement was obtained between predicted and experimental data. 相似文献
102.
电化学生物传感器在农药检测中的应用 总被引:7,自引:0,他引:7
农药包括杀虫剂、杀菌剂、除草剂等,在种植业、养殖业、园林业等领域中有着广泛的应用。全球快速增长的农药使用量给环境、人的身体健康带来了潜在的危害。农药的种类繁多(多达几千种),结构各异,并且在样品中的含量极低(但毒性可能高)。针对这一问题,欧盟提出60多种使用量较大, 相似文献
103.
104.
Development of a class selective immunoassay for the type II pyrethroid insecticides 总被引:1,自引:0,他引:1
A general and broad class selective enzyme-linked immunosorbent assay was developed for the type II pyrethroid insecticides, such as cypermethrin, deltamethrin, cyhalothrin, cyfluthrin, fenvalerate, esfenvalerate and fluvalinate. Polyclonal antibodies were generated by immunizing with a type II pyrethroid immunogen ((RS)-α-cyano-3-phenoxybenzyl (RS)-cis,trans-2,2-dimethyl-3-carboxyl-cyclopropanecarboxylate) conjugated with thyroglobulin. Antisera were screened against nine different coating antigens. The antibody-antigen combination with the most selectivity for type II pyrethroids such as cypermethrin was further optimized and tested for tolerance to co-solvent, pH and ionic strength changes. The IC50s of the optimized immunoassay were 78 μg l−1 for cypermethrin, 205 μg l−1 for cyfluthrin, 120 μg l−1 for cyhalothrin, 13 μg l−1 for deltamethrin, 6 μg l−1 for esfenvalerate, 8 μg l−1 for fenvalerate and 123 μg l−1 for fluvalinate. No cross-reactivity was measured for the type I pyrethroids such as permethrin, bifenthrin, phenothrin, resmethrin and bioresmethrin. This assay can be used in monitoring studies to distinguish between type I and II pyrethroids. 相似文献
105.
《Journal of separation science》2003,26(14):1269-1272
Carbendazim residues were analyzed by column‐switching high‐performance liquid chromatography (HPLC) with photodiode array detection (PDA). The active ingredient was extracted by matrix solid‐phase dispersion (MSPD) from wheat grain on an acidic silica gel column using a methanol‐dichloromethane mixture. The recovery rate for fortified samples was 87.3 ± 3.3% with a standard deviation (SD) of 2.9%. The detection limit was 0.02 μg/mL. The method was applied to the determination of carbendazim residues in wheat grain samples from a treated field. 相似文献
106.
T. A. Berger 《Chromatographia》1995,41(5-6):133-140
Summary Five sulfonylurea herbicides were separated by SFC on both a 25 cm and a 1.6 meter packed column. The former produced rapid
analysis, the latter allowed high resolution of a complex mixture containing the solutes of interest. The solutes were simultaneously
detected with UV, nitrogen-phosphorus (NPD), and electron capture (ECD) detectors. Peaks of breakdown products of sulfonylureas
were characterized by their UV spectra and the presence or absence of nitrogen and chlorine from their NPD and ECD response.
Both parent and breakdown products of sulfonylureas were on-line extracted from large water samples with detection limits
as low as 50 parts per trillion. 相似文献
107.
Antonia Garrido Frenich José Luis Martínez VidalJosé Luis Fernández Moreno R. Romero-González 《Journal of chromatography. A》2009,1216(23):4798-4808
One of the major problems in quantitative analysis of pesticide residues in food samples by gas chromatography–tandem mass spectrometry (GC–MS/MS) is the enhancement or the suppression, of the target analyte signals in matrix extracts. Potentially positive samples, which had previously been identified by a rapid screening method, were quantified using standard addition to compensate matrix effects. As example we performed a systematic study on the application of the standard addition calibration (SAC) method for the determination of 12 pesticides (acephate, bromopropylate, chlorpyrifos, cypermethrin, diazinon, etrimfos, heptenophos, iprodione, methamidophos, procymidone, tetradifon, and triadimefon) in two matrices (cucumber and orange) in the range of initial concentrations of 10–200 μg kg−1. The influence of some factors, such as the minimum number of standard additions used (single, two, three or four points calibration), as well as the known amount of analyte added to the sample, is evaluated in order to obtain reliable results. Accurate quantification is achieved when a single point SAC at 200 μg kg−1 was used, obtaining for all the cases recoveries between 70 and 120%. The proposed analytical approach only needs two injections per sample (blank and spiked extracted sample) to determine the final concentration of pesticide in positive samples. 相似文献
108.
Hassan Sabik Bernard Rondeau Pierre Gagnon Roger Jeannot Katja Dohrendorf 《International journal of environmental analytical chemistry》2013,93(6):457-468
A method combining simultaneous filtration and solid-phase extraction (SPE) with large-volume injection (LVI) in gas chromatography/mass spectrometry (GC/MS) was developed to determine 13 polar pesticides in surface water. The selected pesticides - 4 organophosphorus, 7 organonitrogens and 2 triazine degradation products - were extracted from 0.5-L samples of filtered and raw water using cartridges filled with a silica-bonded material (1 g of ISOLUTE triazine, C-18) and a depth filter. No obstruction was observed during the extraction of raw water drawn from the St. Lawrence River (concentration of suspended particulate matter (SPM) ranging from 2 to 58 mg L?1). Overall percent recoveries were satisfactory for all the target pesticides (>60%) except desisopropyl-atrazine (more polar), which varied from 29 to 46% according to sample pH. The coefficient of variation was below 10% for the majority of the target pesticides and detection limits ranged from 0.1 to 0.8 ng L?1. Applied to real samples drawn from the St. Lawrence River, this method allowed for the detection of atrazine, cyanazine, desethyl-atrazine (DEA), desisopropyl-atrazine (DIA), metolachlor and simazine, at concentrations of 6 to 91 ng L?1. Using atrazine and metolachlor as examples, the correlation between filtered and raw water samples was more significant for the former (r = 0.87) than for the latter (r = 0.67). Temporal variations in atrazine and metolachlor in filtered water drawn from the St. Lawrence River, for example, were similar whether using the established method, based on liquid-liquid large-volume extraction (LVE) combined with GC/NPD analysis, or the one proposed herein. The latter method, however, systematically found atrazine concentrations 62% higher than those obtained by the older one, applied to the same field samples. Thus, the switch to the new analytical method will require the application of a correction factor to the atrazine concentration time series acquired with the previously used method. 相似文献
109.
110.
Miguel Á. González‐Curbelo Samara Dionis‐Delgado María Asensio‐Ramos Javier Hernández‐Borges 《Journal of separation science》2012,35(2):299-307
Analytical potentiality of a modified version of the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method has been studied and validated for the extraction of a group of 11 pesticides (ethoprophos, cadusafos, dimethoate, terbufos, disulfoton, chlorpyrifos‐methyl, fenitrothion, pirimiphos‐methyl, malathion, chlorpyrifos and fensulfothion) and some of their metabolites (malaoxon, disulfoton sulfoxide, terbufos sulfone and disulfoton sulfone) in toasted barley and chickpea flours. The method involves separation and quantification by gas chromatography (GC) with nitrogen phosphorus detection (NPD) using triphenylphosphate as the internal standard. Matrix‐matched calibration was carried out for both flours due to the existence of a matrix effect. Linearity, recovery, precision and accuracy studies of the proposed QuEChERS‐GC‐NPD method were evaluated in each sample matrix. Mean recovery values were in the range of 73–118% with relative standard deviation values below 10%. Limits of detection of the whole method were between 0.07 and 57.39 μg/kg. The method was finally applied for the analysis of 14 samples collected in different zones of the Tenerife island. The residues of pirimiphos‐methyl were found in 13 of them, confirming its unequivocal presence by mass spectrometry. 相似文献