Determination Of Phthalate(PAEs) In Vegetable Oil And Risk Assessment Of Contamination

In recent years,the consumption of edible vegetable oil in China has maintained a rigid growth trend,so the safety of edible vegetable oil has been raised higher and higher.Phthalic acid esters?PAEs?as a kind of commonly used plasticizer are widely used in food packaging,And the hydrophilic of PAEs makes it easy to move from food packaging to edible vegetable oil,.Now there are still some problems in the analysis of phthalate esters in edible oil,such as:abnormal detection equipment,complex sample matrix,large organic reagent consumption,etc.What's more,due to the wide variety of PAEs,there is not much research on the pollution of PAEs in edible oil.To solve these problem,the content of PAEs in edible vegetable oil was analyzed by high performance liquid chromatography combined with diode array detector?HPLC-DAD?.,which is based on a pretreatment method in our reserach group for the determination of phthalate esters in edible oils.The innovation of this method is to use a chemometrics method-multivariate curve resolution alternating least squares?MCR-ALS?-analyzing the chromatographic data,solves the problems of complex matrices,overlapping peaks of interference problems,so that the pollution of phthalate esters in edible oil can be determined accurately.This paper mainly studies the application of a stoichiometric method in the determination of phthalate esters in edible oils and the proportion of PAEs in edible oils and the proportion of individual PAEs.The main content is as follows:?1?This is the first study of the multivariate curve resolution alternating least squares method?MCR-ALS?applied to chromatography data analysis,the total content of PAEs was successfully tested in vegetable oil,the method uses a chemometrics method to analyze the experimental data processing,and we will be required to extract data from the data matrix in complex reach,to get the target analyte with the mathematical purification without complex sample purification process,achieve the principle of“green chemistry”.This experiment first detected the total content of PAEs in 116 kinds of vegetable oil,and there are overlapped peaks in the chromatographic peaks of 116 kinds of vegetable oils caused certain difficulties in the qualitative and quantitative experiments.To solve this problem,the experiment will be applied to MCR-ALS analysis of 27 kinds of vegetable oil which the total PAEs content is relatively high.Among the 27 kinds of vegetable oils,there are 22 kinds of vegetable oils that have PAEs,and the analysis in the other five vegetable oils is not phthalic acid,but other interfering substances.The method was validated under the optimal selected conditions.The linear range of phthalic acid was 0.5¹5?g mL^-1,with a correlation coefficients?r?greater than 0.9992.The LOD and LOQ were 1.0 and 1.3?mol kg^-1,respectively.The recoveries of target analyte in the two levels of spiked samples were in the range of 94%¹06%.The recoveries obtained were in the range of 94¹06%,with relative standard deviations?RSDs?lower than 5.5%.?2?A pretreatment method based on liquid-liquid extraction was established,and the six types of PAEs that were susceptible to contamination in vegetable oil were detected.The method selected two extractants,acetonitrile and carbon tetrachloride.PAEs is extracted from vegetable oil with acetonitrile and extracted from acetonitrile with carbon tetrachloride.The pretreatment method does not require a complex process such as traditional solid phase extraction,and the amount of reagents is less.The analytical method was validated under the optimal selected conditions.As a result,the calibration plot of 6 analytes were found to be linear in the range of 0.01⁵?g mL^-1,with correlation coefficients?r?greater than 0.9994;the detection limit and the quantification limit were 0.05⁰.18?mol kg^-1 and 0.15⁰.54?mol kg^-1.The recoveries of target analyte in the range of 91%¹20%.The repeatabilities,expressed as RSDs,were 15%for intra-day and 14%for inter-day.The results showed that the content of three kinds of PAEs,such as DBP,BBP and DEHP,of only 5 plant oils in 22 plant oils reached the standard,and the content of PAEs in other vegetable oils was higher than the national maximum..