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 ∼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 μM with a correlation coefficient of R2 = 0.9995 (n = 10) and a detection limit of 0.08 μM. 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.