Facile and Sensitive Spectrophotometric Determination of Carbosulfan in Formulations and Environmental Samples

Abstract

Facile, selective and sensitive spectrophotometric method has been developed for the determination of carbosulfan in insecticidal formulations, fortified water, food grains, agriculture wastewater and soil samples with newly synthesized reagents. The method was based on acid and alkaline hydrolysis of the carbosulfan pesticide, and the resultant hydrolysis product of carbosulfan was coupled with 2,6-dibromo-4-methylaniline to give a yellow color product with lambda(max) of 464 nm or interaction with 2,6-dibromo-4-nitroaniline to produce yellow colored product with lambda(max) of 408 nm or coupling with 2,4,6-tribromoaniline to form red colored product has a lambda(max) of 471 nm. Under optimal conditions, Beer's law range for 2,6-dibromo-4-methylaniline (DBMA) was found to be 0.2-12.0 microg ml(-1), 0.6-16.0 microg ml(-1) for 2,6-dibromo-4-nitroaniline (DBNA) and 0.4-15.0 microg ml(-1) for 2,4,6-tribromoaniline (TBA). The molar absorptivity of the color systems were found to be 3.112 x 10(4) l mol(-1) cm(-1) for DBMA, 3.214 x 10(4) l mol(-1) cm(-1) for DBNA and 3.881 x 10(4) l mol(-1) cm(-1) for TBA. Sandell's of the color reactions are 0.013 microg cm(-2) (DBMA), 0.012 microg cm(-2) (DBNA) and 0.011 microg cm(-2) (TBA) respectively. The effect of the non-target species on the determination of carbosulfan was studied to enhance the selectivity of the proposed methods. The formation of colored derivatives with the coupling agents is instantaneous and stable for 28, 30, and 26 h. Performance of the proposed methods were compared statistically in terms Student's F and t-tests with the reported methods.