Wen Ruimei

Measurement of trace phosphorus in dichlorosilane by high-temperature hydrogen reduction gas chromatography

Abstract Dichlorosilane, a gas at normal temperature with a boiling point of 8.3°C, is very difficult to sample and detect using conventional methods. We reduced phosphorus in dichlorosilane to PH3 by hydrogen at high temperature, then PH3 was separated from chlorosilanes by NaOH solution and from other hydrides by chromatographic absorption. Thus the problem of interference of chlorosilanes and other hydrides was overcome and PH3 was measured by a double flame photometric detector at 526 nm. This method was sensitive, reliable and convenient and the sensitivity reached as low as 0.04 μg/l.