A simple spectrophotometric method. for the determination of some organophosphorus insecticides

Abstract

<span style="font-size:14.5pt;mso-bidi-font-size:8.5pt; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">A photometric titration method for th<span style="font-size:12.0pt; mso-bidi-font-size:6.0pt;font-family:HiddenHorzOCR;mso-hansi-font-family:" times="" new="" roman";="" mso-bidi-font-family:hiddenhorzocr;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">e <span style="font-size:14.5pt; mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="">determination of organophosphorus insecticides in their commercial formulations has been developed. In the present method potassium hydroxide hydrolyses oxydemton-methyl, malathion, dimethoate and formothion smoothly and quantitatively in aqueous <i style="mso-bidi-font-style:normal">tert</i>-butanol and the residual alkali is instantaneously transformed into bright yellow potassium benzyl trithiocarbonate (through reaction with carbon disulphide and benzyl mercaptan ) showing λ_{<span style="font-size:17.5pt;mso-bidi-font-size:11.5pt;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">max</span>}<span style="font-size:17.5pt; mso-bidi-font-size:11.5pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"=""> <span style="font-size:14.5pt;mso-bidi-font-size: 8.5pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">at 430 nm.</span></span></span></span></span>