Indirect Determination of Ascorbic Acid by Atomic Absorption Spectroscopy

A new and simple method followed by atomic absorption spectrometry has been developedfor indirect determination of ascorbic acid (AA). The proposed method was based on the oxidationof AA to dehydroascorbic acid with Cu۲+cation(۲۰۰mgL-۱)in an ammonium thiocyanatesolution atpH۲.۴. AA reduces Cu۲+to Cu+followed by the precipitation of Cu+ with SCN-. Then, the excess ofCu۲+in the solution was measured by the atomic absorption spectrometry.The results showed thatAA can be sensitively measured in the linear range of ۲.۰ to ۴۰.۰ mgL-۱ with the detection limit of۱.۵mgL-۱.The relative standard deviation (%RSD) was ۰.۳۱۹ in ۷ determination of ۲.۰ mgL-۱ AA.Finally, the method was successfully used for the determination of AA in tablets containing variousamounts of AA.

Keywords:

Ascorbic acid , indirect determination , atomic absorption spectroscopy