According to HJ637-2012 standard, extract oil substances in the sample with carbon tetrachloride, determine total oil, and then adsorb the extract with magnesium silicate to remove animal and vegetable oils and other substances before determining petroleum. The total oil and petroleum content are both determined by wave numbers of 2930cm^-1(Stretching vibration of C-H bond in CH2 group), 2960cm^-1The stretching vibration of C-H bond in CH3 group and 3030cm^-1Calculate the absorbance A2930, A2960, and A3030 at the spectral bands of the stretching vibration of C-H bonds in aromatic rings. The content of animal and vegetable oils is calculated based on the difference between the total extract and petroleum content.