Polarographic Determination of Sodium Hydrosulfite Residue (Dithionite) in Sugar and Loaf Sugar

In the present paper, differential pulse polarography was applied to determine the dithionite content of sugar and loaf sugar samples. The relevant parameters were studied and optimized. Linearity in the optimized conditions pH = 4.6 (sample solution), pulse amplitude = 0.09 V, and mercury drop size = 4 was 5–40 mg/L (R2 > 0.99). The limit of detection and limit of quantification for standard solution were about 1.40 and 4.66 mg/L, respectively. After optimization, the proposed method was used to determine the analyte in 51 real samples collected from sugar factories in Zanjan, Iran. The sensitivity and accuracy of the proposed method provided acceptable values to determine dithionite in real samples of sugar and loaf sugar. The results showed that the dithionite content in the samples ranged from <1.40 to 13.24 mg/L.