Kinetic spectrophotometric determination of sulfide using whole kinetic curve and a fixed time method

The univariate and multivariate calibration method was applied for the determination of sulfide based on the addition reaction of sulfide with new fuchsin at pH 8 and 25°C. The decrease in absorbance of new fuchsin at 540 nm over a fixed time is proportional to the concentration of sulfide over the range of 0.05-2.5 μg ml⁻¹. The experimental calibration matrix for partial least squares calibration (PLS) method was designed with 20 samples. The cross-validation method was used for selecting the number of factors. The root mean square difference (RMSD) was 0.0843. The effects of various cations and anions on sulfide determination have been investigated.