Kinetic fluorimetric determination of trace hydrazine in environmental waters

Two simple and sensitive methods for rapid determination of hydrazine in water are described, based on the inhibition effect of hydrazine on the reaction of oxyhalogen ion (XO3-) + halogen ion (X-) with rhodamine B in an acid medium. It is found that the linear range and the detection limit for the determination of hydrazine are 7.88 - 78.8 ng mL(-1) and 1.7 ng mL(-1), respectively, in the system of potassium chlorate in hydrochloric acid. They are 3.49 - 78.8 ng mL(-1) and 0.81 ng mL(-1), respectively, in the system of potassium bromate + potassium bromide in sulphuric acid solutions. Recoveries are in the range of 94 - 104%. A comparison was made for the analytical characteristics of different methods, and a possible reaction mechanism was proposed.