introduction Antioxidants are food additives that prevent or delay the oxidative deterioration of food ingredients. They are widely used in edible oils and oily foods to extend shelf life. Antioxidants are mainly classified into natural antioxidants and chemically synthesized antioxidants. At present, only a few natural antioxidants such as vitamin E, tea polyphenols and nordihydroguaiaretic acid have been approved for use by the health department of China. Synthetic antioxidants are widely used because of their low price. Commonly used are butyl hydroxyanisole (BHA), dibutylhydroxytoluene (BHT), tert-butyl hydroquinone (TBHQ), and propyl gallate. These compounds and free radicals can form stable low-energy resonance hybrids, block the mechanism of automatic oxidation chain reaction of oils, and have strong antioxidant properties. At present, China's national standard "GB2760-2011 food safety national standard food additive use standards" in the BHA, BHT and TBHQ limited use, its content should not be higher than 0.2g / kg (calculated in the content of oil) [1]. Excessive use will have adverse effects on the liver, spleen, lungs, etc., and long-term use may lead to cancer such as liver cancer. The method refers to "GB/T23373-2009 food antioxidant butyl hydroxyanisole (BHA), dibutyl hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) determination [2], using GC The -FID method analyzes and detects three common antioxidants in food, which is simple, rapid and sensitive. Test Conditions instrument Trace 1310 GC Gas Chromatograph with FID Detector, TriPlus RSH Autosampler Chromatographic conditions Column: TG-5MS (30m × 0.25mm × 0.25μm) Sample preparation Crush the biscuit food, mix well, accurately weigh 2g sample in 20mL plugged test tube (isolated 0.2g of edible oil sample), add 10mL of n-hexane, ultrasonic extraction for 20min, let stand for 20min, take the supernatant directly GC Analysis (eg turbid, over 0.45 μm membrane). Results and discussion Standard chromatogram and sample chromatogram Linearity, detection limit and RSD The mixed standard solution was prepared at the concentrations of 0.1, 0.2, 0.5, 1.0, 2.0, 5.0, and 10.0 mg/L, respectively, and analyzed by the above methods to investigate the linearity of each component in the concentration range of 0.1-10 mg/L. . The experimental results show that the three components have a good linear relationship at 0.1-10 mg/L, and the linear correlation coefficients are all greater than 0.99 (see Table 1). The same sample was continuously injected for 5 stitches, and the RSD was between 1.32-3.17%, and the repeatability was good. At the same time, the detection limit of each component was calculated by three times the signal-to-noise ratio, and the detection limit of each component was between 0.02-0.05 mg/L (see Table 1). Actual sample testing and standard recovery Buy common foods (Shaqima, ghee cake, cooking oil, etc.) in the supermarket and use this method for testing. The experimental results show that the method can successfully detect three kinds of antioxidants in various foods, and there is no chromatographic peak interference. Antioxidants are commonly detected in various foods and edible oils (see Table 2). At the same time, the food samples and edible oil samples were taken in this experiment, and the spiked recovery experiments were carried out respectively. The spiked concentrations were 0.5, 1.0, 2.0 mg/L, and the recovery of the three antioxidants was investigated. The experimental results show that the recoveries of the components are between 70-120%, which meets the requirements of daily analytical testing (Table 3). to sum up The method was carried out using Thermo Fisher Scientific's new generation TRACE 1310 GC, which fully meets the requirements of detection sensitivity and precision. At the same time, the pretreatment of the method is simple and rapid, the recovery rate of the standard addition is high, the detection sensitivity of the instrument is high, and the linear range is good. references [1] GB 2760-2011 National Standard for Food Safety Standards for the Use of Food Additives [S]. Greenhouse Plastic Plastic Clamps Greenhouse Plastic Plastic Clamps,Greenhouse Structure Connecting Clamps,Agricultural Greenhouses Clamps,Plastic Clamps JIANGSU SKYPLAN GREENHOUSE TECHNOLOGY CO.,LTD , https://www.thgreenhouse.com
Column temperature: 80 ° C (1 min), 10 ° C / min to 250 ° C (0 min), 30 ° C / min to 310 ° C (5 min)
Injection method: splitless injection, the split time is 1min
Inlet temperature: 250 ° C
Carrier gas: nitrogen (99.999%), constant current mode, 1mL/min
FID: detector temperature: 250 ° C, hydrogen flow rate: 35 mL / min,
Air flow rate: 350mL/min, makeup gas: 40mL/min
Injection mode: Liquid injection mode injection volume: 1 μL 
[2] GB/T 23373-2009 Determination of antioxidants butylhydroxyanisole (BHA), dibutylhydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) in food [S].