Rapid determination of total sulfur content in green liquors by turbidimetric method

A turbidimetric method for the determination of total sulfur content in green liquors was developed. The proposed method involves the quantitative conversion of reduced sulfur with hydrogen peroxide to form sulfate at room temperature for 2 min. After barium chloride is added, sulfate instantly reacts with barium chloride to form precipitated barium sulfate that is measured with a UV-Vis spectrophotometer. The interference from carbonate can be eliminated by adding hydrochloric acid. Proper analytical conditions were determined as follows: detection wavelength of 420 nm, the stabilizer of polyvinyl alcohol (PVA), and an analysis time of 10 min. The results showed that the method has an excellent measurement precision (RSD < 1.30%) and accuracy (recovery = 100.1 ± 1.7%) for the quantification of total sulfur content in green liquors. The present method is simple, rapid, and accurate, and can be used for the efficient determination of total sulfur in green liquors.