Analysis of Benzoic Acid Content in Beef

The content of benzoic acid in 1 660 beef samples was determined by liquid chromatography (LC). The result showed that the content of benzoic acid was lower than the limit of quantification (10 mg/kg) in 94.7% of the samples and was greater than 20 mg/kg in the other 5.3%. The levels of benzoic acid and its metabolite hippuric acid in 390 beef samples obtained from slaughterhouses and wholesale markets were determined by ultra-high performance liquid chromatographytandem mass spectrometry (UPLC-MS/MS). The benzoic acid content in 50 confirmed beef samples was less than 0.20 mg/kg. The statistical analysis of the distribution of benzoic acid and hippuric acid in beef indicated that the detection rate of benzoic acid in 340 samples was 62.4% (greater than 12.5 μg/kg), and the content of benzoic acid ranged from nondetectable to 131.41 mg/kg, with an average value of 2.75 mg/kg and a median value of 0.10 mg/kg. The detection rate of hippuric acid was 100.0%, and its content ranged from 5.66 × 10^-3 to 1.15 mg/kg, with an average value of 0.15 mg/kg and a median value of 0.10 mg/kg. Furthermore, risk analysis of benzoic acid residue in beef was carried out based on literature data and the benzoic acid content data obtained, revealing that water injection could be an important risk source that causes high benzoic acid residue levels in beef.