Sampling and determination of carbonyls in stack gas

The GC determination of aldehydes and ketones in stack gas is reported. The stack gas is collected with the dust sampler by isokinetic sampling technique, 2,4-dinitrophenylhydrazine in acidic solution is used to absorb aldehydes and ketones in stack gas specifically, to form their hydrazones, which are determined by GC with a capillary column of SE-54. The GC system can separate nine hydrazones of carbonyls interested with constant recovery rates of 94%-97%, giving lowest detectable limits of 0.05-1.0 ng. The standard gas of carbonyls are determined by this method with relative errors of -5%--10%, percent coefficients of variation within 5%, and spiking recovery rates of 93%-97%. As an application of the method, the carbonyl pollutants are determined in stack gas samples in a chemical plant.