Gas-chromatographic determination of phosphine in ambient air

Abstract

Air samples taken in the neighbourhood of a chemical plant manufacturing dicyanamide from calcium carbide, of which process phosphine is a by-product, were collected in polyester bags and brought to the laboratory for analysis. A gas chromatograph equipped with a nitrogen-phosphorus-selective detector was used. The working range was 0.5–5 p.p.b. (parts per 10⁹)V/V and the detection limit was 0.03 p.p.b. V/V. The stability of the samples was investigated, and different calibration gases were compared. The results obtained with this method in the field agreed with results obtained with a continuous flame photometer.