To establish a method for the determination of azodicarbonamide (ADA) in wheat flour by HPLC.MethodsThe samples were extracted by acetone-dimethyl sulfoxide mixture with ultrasonic oscillations. The ADA separation was carried out on a Hypersil-C₁₈ column (250 mm×4.6 mm, 5 μm) with 10 mmol/L H₂SO₄ solution as mobile phase at a flow rate of 1 ml/min, and detected at 275 nm with a 20 μl injection volume. ResultsThe linear range for ADA was 0.01-1.00 mg/ml, and the correlation coefficient was 0.999 2. The average recovery was 95.9% (RSD<4.3%). The ADA content of 45 samples from Shandong province were lower than the detection limit, which were in line with the current standards.ConclusionThe method was proved to be simple and accurate with good repeatability and high sensitivity, which could apply to the determination of ADA in bulk wheat flour.