A direct method for the polarographic determination of herbicide triasulfuron and application to natural samples and agrochemical formulation

摘要

Polarographic behavior of triasulfuron herbicide in a Britton-Robinson (B-R) buffer was investigated by differential pulse polarography (DPP) and cyclic voltammetry (CV). Optimum conditions for the analytical determination were found to be pH 3.0 at a reduction potential of -1031 mV. Experimental results indicate an excellent linear correlation between the peak current and the concentration in the range of 0.19-11.6 mu g mL(-1) (0.47-28.9 mu M) with a correlation coefficient of 0.993. The limit of detection (LOD) and limit of quantification (LOQ) were obtained as 0.06 and 0.19 pg mL(-1) (0.15 and 0.47 mu M), respectively. The precision of the method is satisfactory at a very low level, and the relative standard deviation (RSD) is 2.37% (n=5). Satisfactory recoveries achieved with spiked soil and dam water samples were between 98.4-103.0% and 100.0-104.0% at concentration ranges of.5.0-25.0 mu g g(-1) and 0.40-2.0 mu g mL(-1) (12.4-62.2 and 1.0-5.0 mu M), respectively, inferring that the established method can be applied to real sample analysis. The method was extended to the direct determination of triasulfuron in agrochemical herbicide formulation Lintur (R) 70 WG and average content of 4.37 +/- 0.16 (n=5)% was in close agreement with the 4.10% quoted by the manufacturer. The influences of some other commonly used pesticides and inorganic salts on the determination of triasulfuron were also examined.