Chemical confirmatory test for organophosphorus and carbamate insecticides and triazine and urea herbicides with reactive imino moieties

Analysis of phenylurea herbicides by capillary GC with NPD detection

“…Gas chromatographic methods usually rely on derivatization procedures. Ogierman [ 51 used trimethylanilinium hydroxide (TMAH) for derivatization; Greenhalgh and KovaCiCova [ 6 ] used methyl iodide for methylation. The urea herbicides are reatively unstable compounds, a property which was utilized by Dornseiffen and Verwaal [7] A direct GC-MS determination of linuron in potatoes has been descrlbed (91 ; the instrumentation may, however, not be available in many control laboratories.…”

Induction of paraoxon dealkylation by hexachlorobenzene (HCB) and mirex

“…The N-H substituent in all cases was converted to N-CH3. The reaction mechanism has been discussed earlier for N-H containing compounds in general (Greenhalgh and Kovacicova, 1975; Lawrence and Laver, 1975).…”

Gas chromatographic determination of carbamate pesticides after flash-heater methylation with trimethylsulfonium hydroxide

“…Their thermolability complicates gas chromatographic (GC) determination by forming the corresponding phenols and other fragments in unreproducible amounts through thermal degradation inside the injector or during the GC run (Thier and Frehse, 1986). Such difficulties may be overcome by using special conditions (Hall and Harris, 1979;Dorough and Thorstenson, 1975) or by derivatization of either the intact substances or the phenols after complete hydrolysis (Greenhalgh and Kovacicova, 1975). Fishbein and Zielinski (1965) described the preparation of thermally stable trimethylsilyl derivatives of some carbamates.…”