Gas chromatographic determination of residual hydrazine and morpholine in boiler feed water and steam condensates

Summary

Hydrazine, an oxygen scavenger in boiler water, was derivatised to the corresponding acetone azine and determined at the ng ml⁻¹ level by gas chromatography. Morpholine, a corrosion inhibitor used in steam boilers, was estimated either directly (if >2.0 μg ml⁻¹) or by quantitative preconcentration (0.1 ng – 2.0 μg ml⁻¹). To obtain symmetrical peaks for these amines, the column packing was coated with KOH. Use of a nitrogen-specific detector improved accuracy of estimation of hydrazine and morpholine, giving a RSD of 1.9–3.6%. Chromatographic analysis of these amines in boiler feed water and steam condensate samples collected from boilers servicing a petroleum refinery is described. Environmental safety regulations calls for monitoring of hydrazine and the methods developed can easily be adapted for this purpose.