The Determination of Ultra-trace Amounts of N,N-Diethylhydroxylamine Residues in Water Used for High-Pressure, High-Temperature Steam Turbines

Oxygen scavengers are usually added to boiler water to stop the steel body of the boiler being oxidized. The choice of an oxygen scavenger must take into account its effectiveness, availability, toxicity and cost. Hydrazine and hydroxylamine are commonly used to inhibit boiler corrosion. Diethylhydroxylamine, (DEHA) has been reported as a useful alternative compound, it is less toxic than hydrazine and hydroxylamine. Consequently the use of this compound as a corrosion inhibitor is likely to increase in parallel with the present-day rising of safety at work standards. Therefore it was decided to develop a method for the determination of diethylhydroxylamine in water samples. The method reported is highly selective, sensitive, and rapid and gives a good reproducibility for the determination of ultra-trace amounts of diethylhydroxylamine residues in boiler water after use of the diethylhydroxylamine as an oxygen scavenger. It allows the diethylhydroxylamine concentrations in water samples to be determined over the ranges 36-460ppb and 178-2140ppb, with a relative standard deviation of less than 1%. The method is based on the inhibition of the bleaching of Remazol Brilliant Blue by oxidation with chloramine-T.