Determination of Phosphorus and Silicon in Edible Vegetable Oil by Inductively Coupled Plasma-Tandem Mass Spectrometry / 分析化学

An analytical method was developed for determination of P and Si in edible vegetable oil using inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS).The microwave-assisted acid digestion of vegetable oil using HNO3 + H2O2 was carried out in closed vessels.The mass spectral interferences were eliminated by O2 mass shift when promoting reaction with O2 inside the collision reaction cell (CRC), and the monitoring of P as 31P16O+ product ion significantly improved the accuracy of the analysis.H2 was added into the CRC for H2 on-mass reaction.The interferences were eliminated by the quadrupole analyzer to accurately identify 28Si+.The effects of the flow rate of O2 and H2 in ORS3 on the signal intensities and BECs of 31P16O+ and 28Si+ were investigated.The optimum O2 and H2 flow rate was determined.Under the optimized conditions, the limits of detection were 0.043 and 0.66 μg/L for 31P16O+ and 28Si+, respectively.The accuracy of the analytical method was assessed by the analysis of the standard reference materials lubricant oil (SRM 1848) from the National Institute of Standard and Technology.No significant differences were observed between the certified values and measured values.This method was used to analyze 5 kinds of edible vegetable oils (rapeseed oil, sunflower oil, peanut oil, corn oil and soybean oil) from different regions of China, and it was found that the content of P was the highest in peanut oil, and Si showed the highest content in soybean oil.

Exposure risk assessment of aflatoxin B1 in edible vegetable oil by using the margin of exposure in Guangxi / 中国食品卫生杂志

Objective This report aims to assess the exposure risk of aflatoxin B1 in edible vegetable oil in Guangxi.Methods By using margin of exposure (MOE),the report analyzes the dietary exposure of aflatoxin B1 in edible vegetable oil with the data from contamination survey and dietary intake survey.Results For the vegetable oil sample,the content of aflatoxin B1 was between 0.50-320.00 μg/kg.The detection rate of peanut oil was 78.08％ (114/146) which was higher than other vegetable oil,and the exceeding rate was 31.51％ (46/146).For peanut oil,the average content was 30.80 μg/kg,the dietary exposure of the population was 17.30 ng/kg BW,and the MOE was 18.For the prepackaged peanut oil samples,the average content of aflatoxin B1 was 6.33 μg/kg,which was below the limit.While for the bulk peanut oil,the average content of AFB1 was 41.50 μg/kg,which was more than 1.08 times of the limit,and the dietary exposure was 25.59 ng/kg BW.The MOE of bulk peanut oil was 12,1/8 of the prepackaged peanut oil.Conclusion Food safety regulators should pay more attention to bulk peanut oil products,the priority in the risk management measures.At the same time,related department should also promote healthy education for the residents.

Determination of Total Fatty Acid Esters of Chloropropanols in Edible Vegetable Oils by Gas Chromatography-Mass Spectrometry / 分析化学

A method was established for the simultaneous determination of the total fatty acid esters of chloropropanols in edible oils by gas chromatography-mass spectrometry combined with isotope dilution technology. The samples were hydrolyzed with sodium methylate-methanol, and then purified by diatomite cartridge. After being derivatized with heptafluorobutyrylimidazole ( HFBI ), the target analytes were determined by GC-MS with the deuteriumchloropropanols esters as the internal standards. An excellent linear correlation in the range of 0. 050-2. 000 mg / L was acquired for 3-monochloropropane-1,2-diol (3-MCPD) esters, 2-MCPD esters, dichloropropan-2-ol (1,3-DCP) esters and 2,3-dichloropropan-1-ol (2,3-DCP) esters, with all the correlation coefficients (r) higher than 0. 9995. The limits of detection (LODs) for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters were 0. 015, 0. 015, 0. 030, and 0. 030 mg / kg, respectively, and the limits of quantitation (LOQ) were 0. 050, 0. 050, 0. 100, and 0. 100 mg / kg, respectively. The average spike recoveries of the four kinds of chloropropanols esters in blank extra virgin olive oil matrix were typically in a range of 87. 0% -110. 5% with the relative standard deviations (RSDs) less than 10. 1% . The detection rates of 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters in 74 edible oil samples were 94. 6% , 63. 5% , 5. 4% , and 0% , respectively. The contamination levels of 3-MCPD esters, 2-MCPD esters and 1,3-DCP esters were in the range of not detected (ND) to 10. 646 mg / kg, ND to 3. 617 mg / kg and ND to 0. 089 mg / kg, respectively. This method is accurate and rugged for the simultaneous determination of total fatty acid esters of chloropropanols in edible vegetable oils.