Sensitive and selective fluorescence determination of trace hydrazine in aqueous solution utilizing 5-chlorosalicylaldehyde.

A facile fluorescent method for the determination of hydrazine in aqueous solution with excellent sensitivity was developed. 5-chlorosalicylaldehyde (CS), a readily commercially available compound, was applied as the derivatization reagent in this work. Under the addition of CS to hydrazine aqueous solution (ethanol/water/acetic acid=30/66/4), an intense fluorescence enhancement was observed at 570 nm with a large stokes shift of approximately 170 nm. Upon the optimal condition, the fluorescence intensity linearly increased with the concentration of hydrazine in the range of 0.2 and 9.3 microM with a correlation coefficient of R2=0.9995 (n=10) and a detection limit of 0.08 microM. The R.S.D. was 2.0% (n=5). Determination of hydrazine in river and drinking water samples was successfully performed. Hydrazine vapor sensing by the proposed method was also reported.