Gas chromatographic determination of 4-benzothienyl N-methylcarbamate

Sample Preparation

“…Pesticidal carbamates and ureas, for example, form trimethylsilyl derivatives with enhanced volatility, thermal stability, and decreased polarity, the latter leading to peaks with less tailing (Fishbein and Zielinski, 1965). Pesticidal carbamates and ureas, for example, form trimethylsilyl derivatives with enhanced volatility, thermal stability, and decreased polarity, the latter leading to peaks with less tailing (Fishbein and Zielinski, 1965).…”

“…Pesticidal carbamates and ureas, for example, form trimethylsilyl derivatives with enhanced volatility, thermal stability, and decreased polarity, the latter leading to peaks with less tailing (Fishbein and Zielinski, 1965). The aryl carbamate pesticide Mobam (4-benzothienyl N-methylcarbamate) and its principal impurity 4-hydroxybenzothiophene are converted to their thermally stable acetyl derivatives by refluxing with acetyl chloride prior to gas chromatography (Epstein et al, 1967). The aryl carbamate pesticide Mobam (4-benzothienyl N-methylcarbamate) and its principal impurity 4-hydroxybenzothiophene are converted to their thermally stable acetyl derivatives by refluxing with acetyl chloride prior to gas chromatography (Epstein et al, 1967).…”

Gas-liquid chromatographic analysis of carbaryl as its N-thiomethyl derivative

“…This derivatization step also offers an opportunity of adding a moiety which enhances the detectability of the carbamate to specific detectors such as the electron-capture or microcoulometric detectors. N derivatives that have been investigated for residue analytical purposes are IV-trimethylsilyl (Fishbein and Zielinski, 1965), iV-acetyl (Epstein et al, 1967;Sullivan et al, 1967; Magallona and Gunther, 1974), IV-trifluoroacetyl (Lau and Marxmiller, 1970), IV-pentafluoropropionyl and jV-heptafluorobutyryl (Seiber, 1972), and the N-mono-, di-, and trichloroacetyl derivatives (Magallona and Gunther, 1977). Westlake et al (1972) used a flame photometric detector (FPD) in the sulfur mode to analyze for RE-11775 (m-sec-butylphenyl jV-methyl-N-thiophenylcarbamate).…”