Determination of L-aspartic acid by using the Cu(II)-catalyzed oscillating reaction

Abstract

A convenient procedure by means of oscillating chemical system as an analytical tool to determine the L-aspartic acid (L-Asp) is proposed. The system involves the Cu(II)-catalyzed reaction between hydrogen peroxide and sodium thiocyanate in an alkaline medium. The method relies on the linear relationship between the changes in the oscillation period and the logarithm of concentration of L-aspartic acid. Optimized conditions were further validated to ensure the reliability of the method. Under optimum conditions, the calibration plot is linearly proportional to the concentration of L-aspartic acid over the range from 1.17 × 10-5 mol L-1 to 7.10 × 10-8 mol L-1 with a corresponding regression coefficient of 0.9990 (RSD 2.75%). A lower limit of determination (LOD) was 5.58 × 10-8 mol L-1. The proposed method has been used to determine L-aspartic acid in drug sample. Additionally, the HPLC technique was also used to confirm the determination results. © 2009 Sociedade Brasileira de Química.