Abstract:A method using element analyzer-isotope ratio mass spectrometry (EA-IRMS) was established to analyze the stable hydrogen and carbon isotope ratios (δ2H and δ13C, respectively) of 13 corn oil, 20 soybean oil, 20 peanut oil, and 15 blend oil samples. The results showed that δ13C values of corn oil, soybean oil, and peanut oil samples were -30.475‰ to -14.15‰, -30.11‰ to -25.103‰, and -29.775‰ to -24.44‰, respectively. The δ13C values were significantly different among samples of the three kinds of vegetable oils (p<0.01). After eliminating possible adulterated samples, the δ2H values of the corn oil, soybean oil, and peanut oil samples were -277.431‰ to -261.493‰, -262.658‰ to -232.687‰, and -290.164‰ to -231.233‰, respectively. The δ13C values of the corn oil, soybean oil, and peanut oil samples were -16.606‰ to -14.15‰, -25.98‰ to -25.103‰, and -29.775‰ to -26.032‰, respectively. Significant differences were observed in the δ2H and δ13C values among samples of the three kinds of vegetable oils (p<0.01). In addition, blend oil displayed a wide distribution of δ2H values ranging between -260.033‰ and -220.234‰. Comparison of the two-dimensional distribution of carbon and hydrogen isotope ratios of blend oil with those of the other three kinds of vegetable oils can contribute towards comprehensively evaluating and identifying adulterated commercial vegetable oil samples and can provide a foundation for research and technical support for determining adulteration in commercial vegetable oils.
