Determination of chloride by multisyringe flow injection analysis and sequential injection analysis with potentiometric detection

Abstract

This paper reports for the first time a multisyringe flow injection analysis (MSFIA) method with potentiometric detection for the automated determination of chloride in waters. The methodology developed was applied to the determination of chloride in mineral, tap and waste waters and the results achieved were compared with those obtained by a potentiometric sequential injection analysis (SIA) method reported in the literature. When Mohr titration was carried out for validating the results offered by both techniques, no significant differences were found. The linear ranges were between 6 and 3500 mg l −1 for MSFIA and 10 and 3500 mg l −1 for SIA; the UPAC limits of detection were 2.7 mg l −1 for MSFIA and 1.6 mg l −1 for SIA; reproducibility was ca. 0.8% for MSFIA and 0.4% for SIA and, sampling rates were of 30 and 15 injections h −1 for MSFIA and SIA, respectively. These results provide evidence of superior performance of MSFIA over SIA for the determination of chloride.