Abstract:Benzo[a]pyrene (BaP) is widespread in the industrial sewage from coal tar and oil refining; vegetable oil subjected multiple times to a high temperature as well as charred food may also contain BaP. The permissible limit of BaP in China for edible vegetable oil products is below 10 μg/kg. At present, the most widely used methods for quantification of BaP in food are high performance liquid chromatography, gas chromatography with mass spectrometry, and some others. Nonetheless, in the above methods, sample pretreatment is complicated, measurement time is long, and measurement efficiency is low; therefore, they still cannot meet the requirements for real-time and in situ analysis.Rapid quantification of BaP in edible oil by surface enhanced Raman spectroscopy (SERS) was studied here by means of nanogold-modified porous materials as a SERS substrate. A linear relation between the peak area of SERS and the concentration of BaP was obtained in the range of 0~200 μg/L. The linear equation was y= 134.98x–571.77 (R2=0.9942). At a concentration of 10 μg/kg, the recovery rates of samples ranged from 93.2% to 125.7%, and the relative standard deviations (RSDs) were between 10% and 18%. The detection limit of the SERS method was 5.6 μg/L. The analysis of BaP by the SERS method could be carried out on site using a portable Raman spectrometer, and measurement time was short (generally tens of seconds to one or two minutes). The SERS method provides a new option for rapid quantification of BaP in edible oils if the analytical sensitivity meets the requirements.
