Spectrophotometric determination of chloride in mineral and drinking waters using sequential injection analysis

An on-line sequential injection system has been developed for spectrophotometric determination of chloride in drinking mineral, natural, and ground waters. Samples containing different concentrations of chloride were analyzed. The analysis is based on detection of the red iron(III) thiocyanate complex. The complex was monitored spectrophotometrically at 480 nm using de-ionized water as the carrier stream at a flow rate of 3.21 mL min(-1). The method was found to be linear within the range 0-50 mg L(-1) chloride; the detection limit was 3.01 mg L(-1). The fully automated method can be used to analyze 37 samples per hour with a relative standard deviation (RSD) better than 2.50%.