Abstract:

A method was developed for simultaneous determination of ammonia, hydrazine and ethanol amine in air by suppressed conductivity ion chromatography (IC). The method was applied to evaluate the safety of workplace air. The ammonia, hydrazine and ethanol amine were absorbed with methyl sulfonic acid (MSA) aqueous solution as absorbing solution. The water-insoluble particles were removed by 0.22 μm filter membranes. The separation was performed on ThermoFisher IonPac CS19 carboxylic acid type cation exchange chromatographic column (250 mm×4 mm) and CG19 guard column (50 mm×4 mm). MSA was generated as mobile phase by eluent generator, and isocratically eluted. Suppressed conductance has been selected as the principle for detection of the three compounds simultaneously. The results showed that the precisions of ammonia, hydrazine and ethanol amine were between 0.98% and 1.6%, and the limits of detection (LODs) of ammonium, hydrazine and ethanol amine were 0.003, 0.011 and 0.016 mg/L, respectively. It is a simple, quick and accurate method without any complex pretreatment such as derivatization. The separation of ammonium, hydrazine and ethanol amine can be completed in 15 min. The method can shorten the detection time and improve work efficiency. It has a high practical application value.

Key words: air, ammonia, ethanol amine, hydrazine, ion chromatography (IC)