Abstract: Sodium formaldehyde sulfoxylate is a chemical raw material prohibited to be added into food as a food additive,There.There is no national standard method for determination of sodium formaldehyde sulfoxylate in wheat flour so far.In this paper,the background values of 122 wheat flour samples were determined with the method recommended by General Administration of Quality Supervision,Inspection and Quarantine in 2002.It was expected that the values can provide scientific principles for inspecting sodium formaldehyde sulfoxylate content in wheat flour.The average background value of the(formaldehyde in 122 wheat flour samples is 3.85mg/kg and the variations range is between 0.92mg/kg and 6.77mg/kg.For the 95% probability,the confidence interval range for the 122 wheat flour samples is from 1.40mg/kg to 6.31mg/kg,whereas the maximum confidence value of 6.31mg/kg can function as the background value of wheat flour this way.

Key words: flour, formaldehyde, background, sodium formaldehyde sulfoxylate