Flow-Injection Chemiluminescence Determination of Thiosemicarbazyl Compounds in Insecticides.

This paper reports a sensitive, simple and rapid flow injection chemiluminescence method for the determination of thiosemicarbazyl compounds in insecticides. It was found that the thiosemicarbazyl compounds have the tendency to inhibit the Chemiluminescent (CL) signal generated by KMnO4 - Na2SO3 system in the acidic medium. The linear correlation between the generated CL and the concentration logarithm was detected in the range of 7.3 x 10-9 - 5.4 x 10-7 M for Thiosemicarbazide (TSC) and 6.8 x 10-9 - 3.6 x 10-7 M for the thiosemicarbazone; with the relative standard deviation (for 12 measurements) of 2.3% and 2.6% respectively. The limits of detection (3σ) are 2.2 x 10-10M and 1.8 x 10-10M respectively. The sample throughput is 100 samples/h. The proposed method was used to determine the TSC in the synthetic samples with satisfactory results. To prove the practical use of the method, it was applied to determine the TSC and thiosemicarbazone concentrations in insecticides purchased in the market. [ABSTRACT FROM AUTHOR]