Mechanism of atomization interference by oxygen at trace level in miniature flame hydride atomizers

The mechanism of atomization interference by oxygen at trace level in gases supplied to miniature argon hydrogen diffusion flame (MDF), flame-in-gas-shield (FIGS) and flame-in-flame (FIF) hydride atomizers, was investigated for hydrogen selenide, arsine and stibine. A continuous flow hydride generation system coupled with atomic absorption detection was employed. The effect produced by oxygen contamination, intentionally added to gases as contaminant (0-1290 μl l− 1), on spatial distribution of free atoms, on sensitivity and signal shape observed for MDF, FIGS and FIF in different atomization conditions and on the shape of calibration graphs was investigated. The oxygen contaminant reacts with hydrogen radicals reducing their concentration and the size of hydrogen radical cloud. Simultaneously, the rate of free analyte atom reactions is enhanced. Both these factors lead to the decrease of free analyte atom population.