Gas chromatographic determination of pentachloromandelnitril(PCMN) in wettable powder and dust

A method was proposed for the gas-liquid chromatographic determination of PCMN in wettable powder and dust. PCMN was extracted with acetone and determined by gas chromatography by using a thermal conductivity detector and dibutylphthalate as internal standard. The column temperature was adjusted to 230°C and the flow rate of carrier, helium, was maintained to be 50 ml/min. PCMN was converted quantitatively to pentachlorobenzaldehyde in the gas chromatographic operation. Pentachlorobenzaldehyde initially present in commercial PCMN as an impurity caused positive error but could be eliminated by thin layer chromatographic separation before the analysis. The results showed good agreement with those by pyridinepyrazolone method as in Table II. Those of recovery test were shown in Table I. The calibration curve in the 0.72.3 weight ratio (PCMN/DBP) was almost linear.