Analytical Methods And Population Exposure Characterisation Of Typical Plasticisers And Flame Retardants In Hair Samples

Objective1.To develop a method for the combined detection of 19 phthalates or phthalic acid esters（PAEs）and 10 of their metabolites（m PAEs）in human hair based on high performance liquid chromatography coupled with mass spectrometry（HPLC-MS/MS）.2.To understand the levels of exposure to plasticisers and flame retardants in the population and their compositional characteristics.3.To analyse the factors and correlations between compounds that may influence the concentration levels of plasticisers and flame retardants.Methods1.The mass spectrometric conditions for the analysis and quantification of the target analytes were optimised using HPLC-MS/MS during the development of the plasticiser assay,and the hair washing process and extraction solvents were optimised.2.Hair samples were collected from a population of Jinzhou,Liaoning and Nandan,Guangxi using whole-group sampling to analyse the concentrations and congener composition of phthalates and their metabolites,organophosphorus flame retardants（OPFRs）and tetrabromobisphenol A（TBBPA）in hair.（TBBPA）and their congeners.3.One-way ANOVA was used to analyse the differences in the concentrations of PAEs,m PAEs,OPFRs and TBBPA in hair samples between regions,sexes and age groups.Spearman’s correlation test was used to correlate the concentration levels of plasticisers and flame retardants in hair.Results1.Optimisation of the method for the analysis of plasticisers in hair: The optimised method met the analytical requirements for the analysis of plasticisers in hair and allowed the accurate quantification of 19 phthalates and10 of their metabolites.The recoveries were 59^-124 % and 83^-114 % for low spiked（20 ng）matrix samples and 56^-135 % and 83^-127 % for high spiked（200 ng）matrix samples,respectively,and the method limits of detection were0.044^-18 ng-g^-1 and 0.08-0.41 ng-g^-1,respectively.2.Exposure levels of plasticisers in human hair:（1）∑₁₉PAEs ranged from2211^-134336 ng·g^-1 with a median value of 11422 ng·g^-1;∑₁₀m PAEs ranged from ND-2157 ng·g^-1 with a median value of 51 ng·g^-1;∑₈OPFRs ranged from2.5 to 28505 ng·g^-1 with a median value of 243 ng-g^-1;TBBPA ranged from ND to 148 ng·g^-1 with a median value of 2.6 ng-g^-1.（2）PAEs in human hair were mainly detected by DEHP with a concentration of m PAEs in human hair were mainly detected by MEHP（48 %）,followed by MBP（25 %）and Mi BP（13 %）;OPFRs in human hair were mainly detected by TCIPP（29 %）,followed by TDCIPP（26 %）,TEHP（17 %）and TPHP（13 %）.and TPHP（13 %）.3.Analysis of the factors affecting the exposure levels of plasticisers and flame retardants in the hair of the population showed that no significant differences were found in terms of region（p>0.05）;in terms of gender,the concentration levels of plasticisers in the hair of women were found to be significantly higher than those of men（p<0.05）;in terms of age,the concentration levels of plasticisers and flame retardants in the hair of the younger group（<60 years）were found to be significantly greater than those of the older group（≥60）（p< 0.05）.4.Correlations were found between most of the congeners.No correlation was found between ∑₁₉PAEs and ∑₁₀m PAEs（p>0.05）,and a weak correlation was found between two flame retardants,OPFRs and TBBPA（p< 0.05）.Conclusions1.In this study,an analytical method based on HPLC-MS/MS was developed for the determination of 19 PAEs and their 10 m PAEs in hair,and all parameters were met.The method allows simultaneous extraction of PAEs and m PAEs,improves the efficiency of pre-treatment,provides rapid and accurate detection of the target contaminants,and is suitable for the determination of PAEs and m PAEs in hair and the assessment of phthalate exposure in the population.2.PAEs and OPFRs were detected in all hair samples,and m PAEs and TBBPA were found in most samples,indicating widespread exposure of the population to plasticisers and flame retardants.Exposure levels of ∑₁₉PAEs in human hair were the highest of the four compounds in this study and require ongoing attention.3.The widespread detection of m PAEs suggests that PAEs are converted to m PAEs in human metabolism and enter the hair,indicating the potential of hair as a biomonitoring tool for human exposure.4.Gender differences had the greatest impact on the fugacity of the target compounds,with women having higher levels of PAEs in their hair than men and women being more vulnerable to plasticiser exposure.Age also had an effect on the fate of the target compounds,with those aged less than 60 years more likely to be exposed to plasticisers and flame retardants.