Spectrophotometric determination of arsenic in environmental and biological samples

摘要

A simple and sensitive Spectrophotometric method has been developed for the determination of arsenic using variamine blue as a chromogenic reagent.The method is based on the reaction of arsenic(III) with potassium iodate in acid medium to liberate iodine,which oxidizes variamine blue to form a violet coloured species having an absorption maximum at 556 nm.Beer's law is obeyed in the range 0.2-14 mu g mL~(-1) of As(III).The molar absorptivity,Sandell's sensitivity,detection limit and quantitation limit were found to be 1.43x10~4 L mol~(-1) cm~(-1),5.26x10~(-2) mu g cm~(-2),0.022 and 0.072 mu g mL~(-1),respectively.The optimum reaction conditions and other analytical parameters were evaluated.The proposed method has been successfully applied for the determination of arsenic in various environmental and biological samples.