Preparation of Reagents for the Sensitive Spectrophotometric Determination of Carbaryl in Environmental Samples

Abstract

A simple and sensitive spectrophotometric method was described for the determination of carbaryl in its formulations, fortified water, food grains, polluted water, plant material (cabbage), soil, and biological samples (blood and urine) with the prepared coupling reagents. The method was based on alkaline hydrolysis of the carbaryl pesticide, and the resultant hydrolysis product of 1‐naphthol was coupled with 2,6‐dibromo‐4‐methylaniline to give a purple product with λmax of 505 nm or coupling with 2,4,6‐tribromoaniline to produce a violet colored product with λmax 535 nm or coupling with 2,6‐dibromo‐4‐nitroaniline to form pale‐red colored product has a λmax of 492 nm. The formation of colored derivatives with the coupling agents are instantaneous and stable for 48 h, 40 h, and 36 h, respectively. The results indicate the proposed method's sensitivity, selectivity, and the recovery of the carbaryl from the fortified water, food grains, polluted water, plant material (cabbage), soil, and biological samples (blood and urine) are higher than the other methods. The authors thank Bayer (India) Ltd., Bombay, for the supply of technical grade carbaryl and the Head of the Dept. of Biotechnology, S. V. University, Tirupati for providing instrumental facility to carry out this work.