Spectrophotometric Determination of Sodium Dodecyl Sulfate based on Ion-Pair Extraction with Copper (II) Complex Ion of 1, 10-Phenanthroline

Abstract

A simple and rapid spectrophotometric method was developed for the determination of sodium dodecyl sulfate (SDS). The method was based on formation of the SDS- [Copper (II) -1, 10-phenanthroline] ion pair and extraction into isobutyl methyl ketone (MIBK). The ion pair in MIBK was reduced with 1-butanethiol to form an intensely colored copper (I) complex. By this method, the overall concentration of SDS can be determined indirectly from the absorbance of copper (I) complex formed in MIBK. The calibration curve was linear over the range of the detection limit from 8.3 × 10-7 to 6.3 × 10-5 M of SDS. The relative standard deviation of nine successive determinations was 1.02 % at 2.5 × 10-5 M of SDS. The sensitivity of the proposed method is comparable to that of the indirect atomic absorption method for SDS which is accepted as a highly sensitive method.