To develop a determination and verification method for DBS in gutter oil and its application. Methods After extracted by 50% ethanol and purified by SPE column, the DBS in gutter oil was detected by HPLC, separated by a Nucleodur C₁₈ column(250mm×4.6mm×5μm) with mobile phase consisting of methanol (containing 20% 10mmol/L ammonium acetate). Verification was operated by LC-IT-TOF mass spectroscopy in ESI-ionization model, nebulizing gas was 1.5ml/min and detector voltage was 1.68kV. ResultsQuantity of DBS in gutter oil was accuratly determined in the range of 4.030-503.3μg/ml, the recoveries were 77%-87% and RSD% of precision was less than 2%. All 7batches of gutter oils and 23batches of edible oils matched the results of verification. Conclusion The method was suitable for the detection of DBS in gutter oil.