Distribution Characteristics And Dietary Risk Assessment Of Phthalates And Their Metabolites In Porcine Tissues

Phthalate esters(PAEs)are the most commonly used plasticizers in industrial production,which are easy to migrate from plastics,accumulate or rapidly metabolize into monoalkyl phthalate esters(MPEs)in organisms.Studies have shown that PAEs,as an environmental hormone,has endocrine disruptor toxicity on human body and neurotoxicity and carcinogenic teratogenic mutagenicity on organisms.As PAEs metabolites,MPEs have stronger biological activity and greater biological toxicity.At present,various countries and international organizations have successively issued a series of standards and regulations restricting the use of PAEs,established the detection methods of PAEs in food,and stipulated the limits of some PAEs,but few reports have been reported on the detection methods of PAEs and its metabolite MPEs in animal food,especially meat and internal organs.Therefore,it is of great significance to simultaneously carry out studies on the detection methods and risk assessment of PAEs and their metabolites MPEs in animal-derived food.With the improvement of residents’ consumption level,the consumption of pork and characteristic visceral food in China is increasing day by day,and China has become the first big country of pork and visceral food consumption.However,the current focus on PAEs in pig tissues is only limited to the six PAEs under the preferential control,while there are few studies on PAEs and metabolite MPEs under the non-preferential control.In order to solve this problem,this study on the basis of the existing national standard method and the research method is optimized,and established the pork and viscera of 22 kinds of PAEs in solid phase extraction-gas chromatography-tandem mass spectrometry(SPE-GC-MS/MS)analysis method,and eight kinds of MPEs in pork and viscera SPE-liquid chromatography-tandem mass spectrometry(SPE-LC-MS/MS)analysis method.On the basis of the established methods,this study studied the pollution level,distribution characteristics and correlation of PAEs and MPEs in 6 tissues(heart,liver,spleen,lung,kidney and meat)of pigs in large-scale breeding plants.Meanwhile,the contamination levels of phthalates in pork,liver,kidney and other organs were investigated,and the risk of dietary intake was evaluated.The research results show that:(1)Two acetonitriles were used,and then ultrasonic extraction was conducted and purified by PSA/silica glass solid-phase column.The recovery rate of three PAEs with different concentrations(10,50,100 ng/g)was 80% to 114%,RSD was less than or equal to 4.9%,and the LOQs andLODs of 22 PAEs in pig tissues were 0.32-12.0 ng/g and 0.097-3.61 ng/g respectively.The spe-gc-ms /MS method can realize the trace analysis of 22 kinds of PAEs in the sample.Established the beta glucuronidase digestion and MAX before the combination of solid phase extraction small column purification processing method,using five fluorinated phenyl(PFP)chromatographic column,0.1% formic acid acetonitrile and 0.1% formic acid as mobile phase,the water in the three different concentrations of adding level(10,25,100 ng/g)recovery was 64.9%-106.7%,relative standard deviation is less than or equal to 7.4% of pigs in the organization quantitative limit of 8MPEs(LOQs)and the detection limit(LODs)were 0.2-1.9 ng/g and 0.01-0.6 ng/g,The established SPE-LC-MS/MS method solved the trace analysis of 8 kinds of MPEs in porcine tissues.(2)A total of 8 PAEs and 5 MPEs were detected in all porcine tissues in the large-scale breeding plant.Among them,the detected concentrations of DEHP and its secondary metabolites MEOHP,DBP and their metabolites MBP were significantly positively correlated(p<0.01),and the detected concentrations of DEP and their metabolites MEP were significantly positively correlated(p<0.05).In pork,DMP and its metabolites MMP,DEP and their metabolites MEP,DBP and their metabolites MBP and DEHP were significantly positively correlated with their metabolites MEHP(p<0.05).In other tissues,except for the significant positive correlation between DEHP in the heart and its MEHP metabolite,PAEs detected were correlated to some extent with their corresponding MPEs,but the correlation was not significant.(3)The sale of pork and liver and kidney in both exist certain phthalates pollution,with dimethyl phthalate(DMP),diethyl phthalate(DEP),butyl phthalate(DBP),among them the highest concentrations of DMP in pork liver,up to 1521.3 ng/g,and in the pig kidney DMP highest concentration of 1479.6 ng/g.The highest concentrations of DBP in the pork was 1330.7 ng/g.Phthalate butyl ester(DIBP)and phthalate heptyl ester(DHP)in pork concentration level is higher,and the maximum detection concentrations were 927.4 ng/g and 1517.9 ng/g,respectively.Non-carcinogenic risk assessment was conducted on PAEs with clear toxicological data,and the risk quotient of all samples was less than 2.66×10-2.Meanwhile,the carcinogenic risk assessment was conducted on DEHP,and the excess cancer risk index of all samples was less than 5.00×10-5.To sum up,this study established an analytical method for 22 kinds of PAEs and 8 kinds of MPEs in pig tissues,and obtained the recovery rate at high,medium and low concentration levels with high accuracy and sensitivity,realizing the simultaneous determination of PAEs and MPEs.On this basis,the correlation analysis of PAEs and MPEs in pig tissues was carried out,and it was found that MPEs could be used as a qualitative indicator of PAEs in pig liver and pork.Through investigation and analysis,it was found that there were certain PAEs and MPEs in pork,liver and kidney sold in Beijing,and the dietary exposure level was still within the acceptable range.However,because the toxicological data of the metabolite MPEs were not clear,no model had been established to convert MPEs into PAEs,so the risk of PAEs should not be ignored.