Analysis of pesticide residues by chemical derivatization. II. N-methylcarbamates in natural water and soils
Coburn, J.A.; Ripley, B.D.; Chau, A.S.
Journal - Association of Official Analytical Chemists 59(1): 188-196
1976
ISSN/ISBN: 0004-5756 PMID: 2579 Document Number: 102207
The method described involves extraction of the carbamates from the substrate, followed by basic partitioning to remove free phenols and acids. After the carbamates are hydrolyzed in a methanolic potassium hydroxide solution, the resulting phenols are extracted from the hydrolysis solution and derivatized with pentafluorobenzyl (PFB) bromide to form the PFB ether derivatives. These derivatives have been shown to exhibit excellent electron capture responses and to be amenable to gas-liquid chromatographic (GLC) separation on commonly used liquid phases (24-29). This reagent is more specific than some of the stronger acylating agents and has been found to be stable in solution for several weeks. Excess reagent is removed and the derivatives are fractionated on a silica gel microcolumn. The various column fractions are then analyzed by electron capture GLC.