Analysis of triallate residues in cereals and soil by gas chromatography with ion-trap detection.
Triallate residues in barley seedlings and soil samples were determined by gas chromatography with ion-trap detection. Soil was extracted with methanol on a mechanical shaker, and plants were extracted with acetonitrile in a Sorvall homogenizer. After evaporation of the organic solvents, the residue was dissolved in hexane, and plants extracts were cleaned-up on an alumina column. Gas chromatographic analysis was carried out using a BP-1 fused-silica capillary column with helium as carrier gas. To quantitate residues the total-ion chromatogram was obtained and then the selected-ion monitoring chromatograms were displayed at m/z 86 for triallate and at m/z 154 for the internal standard, methyl-(4-amino-2-chloro)-benzoate. The average recovery through the method from barley and soil samples was always higher than 80%. The limit of detection in the selected-ion mode was 0.01 mg/kg. Barley and soil samples treated with triallate were also analysed. A good agreement was observed between results obtained by this method and by gas chromatography with nitrogen-phosphorus detection.
Herbicide Residues in Biota, Analysis of
Current extraction, derivatization and clean-up techniques, and instrumental methods are reviewed for the analysis of herbicide residues in biota. Sampling procedures are shown to be an integral part of the methodology. Herbicide analysis is seldom based on analyte-specific methods but is usually integrated into multiresidue methods (MRMs). Current methods generally utilize relatively small sample sizes and miniaturized apparatus to take advantage of advances in instrumental performance and detection of analytes. These methods reduce the amount of solvent used for sample preparation and help to minimize waste generation. As well as using less solvent, the resulting miniaturized methods tend to be generally cheaper, faster, and less labor-intensive than conventional methods and, furthermore, they reduce analyst exposure to hazardous materials. 
 
 
 
Mass spectrometry (MS), interfaced with high-resolution gas chromatography (GC), high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE), has become the detection method of choice for herbicide analysis. MS is well suited to the confirmation of target analytes and the tentative identification of unknown analytes. HPLC–mass spectrometers are becoming more widely available and less expensive. CE is a relatively new separation technique providing many advantages over traditional gas and liquid chromatography, including shorter analysis times and smaller injection volumes. There have been advances in the development of immunoassays primarily for the rapid screening for herbicide residues. These methods, once optimized, can facilitate high sample throughput at relatively low cost compared to conventional approaches. To date however, development has been limited to aqueous systems and little immunoassay work has been done for the direct determination of herbicides in biota.
Analysis of Pesticide Residues
A comprehensive guide to the latest techniques and applications of pesticide trace analysis. Methods covered include gas, thin layer, and high-performance liquid chromatography, along with their applications in the analysis of chlorinated hydrocarbons, acidic herbicides, organophosphates, carbamates, and insect pheromones and hormones. Includes a special chapter on residue data requirements of government agencies.