Determination of indole in shrimps by differential-pulse voltammetry in an emulsified medium

A method has been developed to determine indole in shrimps by differential-pulse voltammetry at a Pt electrode in an emulsified medium, after extraction into hexane - ethyl acetate (49 + 1). The standard additions method was used in order to minimise the matrix effect. Recoveries at the concentration levels of 11.71 and 0.94 micrograms g-1 of shrimp were 82 and 75%, respectively. The relative standard deviations were 3.5 and 4.0%, respectively. The accuracy of the proposed method was verified by comparing the results obtained from the analysis of shrimp samples allowed to decompose at room temperature for 1, 3 and 4 d, with those obtained from a spectrophotometric method by applying Student's t-test.