Determination of ametryn in sugarcane and ametryn-atrazine herbicide formulations using spectrophotometric method.

A sensitive spectrophotometric method has been developed for determination of ametryn in agricultural samples. The proposed method was based on reaction with pyridine and further coupling with sulfanilic acid to form a colored product. The absorbance was measured at 400 nm with a molar absorptivity of 2.1 x 10(5) L mol(-1) cm(-1). The method shows a linear range from 0.2-20 μg mL(-1) with limit of detection and limit of quantification 0.16 and 0.54 μg mL(-1), respectively. The method has been successfully applied to the determination of ametryn in sugarcane juice and commercial formulations after separation of ametryn from triazine herbicides based on solvent extraction. Recovery values were found to be in the range of 96.0 ± 0.2% to 98.4  ±  0.1%.