Abstract:

A novel method was developed to determine sodium formaldehyde sulfoxylate residues in wheat flour and starch
noodles without degradation. The samples were extracted ultrasonically with water and the extracted analytes were separated
by capillary electrophoresis (CE) in combination with capacitively coupled contactless conductivity detection (CE-C4D).
Under optimal conditions, the linear range was 1.00–200 μg/mL (r2 = 0.999 8), and the limit of detection for both food
matrices was 10 mg/kg. Recoveries varying from 84.0% to 94.7% with a relative standard deviation (RSD) smaller than
5% were achieved for the analyte spiked between 20 and 100 mg/kg. The proposed method was simple and rapid. It has
beensuccessfully applied for analysis of sodium formaldehyde sulfoxylate in wheat flour and bean starch noodles.

Key words: capillary electrophoresis, contactless conductivity detection, sodium formaldehyde sulfoxylate, direct determination