| Methylsiloxanes are a class of organic compounds consisting of—Si(CH3)2—O—repetitive units,which are widely used in various industrial fields.As new polluants in environment,some methysiloxanes have attached much attention due to their high volatility,high fat solubility,environmental persistence,bioaccumulation and endocrine disruption.The homologues of methysiloxanes are abundant.They exist in a variety of matrixes with large differences in content.They had been detected in a variety of environmental samples,personal care products,silicone products and human body samples.Exposure of methylsiloxanes to human body mainly includes respiratory exposure,skin exposure,oral exposure and internal implantation exposure.In order to further study of the possible health risks to human health caused by methylsiloxanes through oral exposure,in this research,the food-contact silicone products(teats and moulds)and fried food(chicken and chips)was respectively used as research subjects,methylsiloxanes and their migration were analyzed,and their oral exposure assessment were carried on.It mainly included:(1)The qualitative and quantitative analysis methods of 32 kinds of methylsiloxane in food-contact silicone products were established by using ultrasonic solvent extraction-GC/MS.The methylsiloxanes in 59 silicone products including 32 teats and 27 piece of moulds were analyzed.Linear methylsiloxanes(L3-L14)and cyclic methylsiloxane(D3-D22)were identified by various qualitative methods.Quantitative results showed that the average concentrations for LMS(L3-L14)and CMS(D3-D22)in teats ranged from 0.12(L4)—39.05(L10)?g·g-1and 0.18(D4)—107.41(D15)?g·g-1,with the detection frequencies ranging from 38%(L5)to 100%(D12);On the other hand,the average concentrations for LMS and CMS in moulds ranged from 0.08(L4)—2.29(L9)?g·g-1and 0.04(D4)—92.51(D14)?g·g-1,with the detection frequencies ranging from 4%(L6)to 100%(D6).The total amount of methylsiloxanes in teats was as high as 656.555?g·g-1.Therefore,infants and young children in this especial group may face a high risk of oral exposure to methylsiloxane during use of teats.(2)A highly sensitive and sensitive detection method of methylsiloxane in artificial saliva and infant formula were established by using solvent extraction-GC/MS and Qu ECh ERS(orthogonal test design)-GC/MS.The migration of methylsiloxanes from 22teats into artificial saliva and formula milk was analyzed,respectively.The results showed that 33 methylsiloxanes were detected and the limit of detection ranged from 0.17 ng·m L-1(L4)to 0.54 ng·m L-1(L7).The average concentrations for LMS and CMS in artificial saliva,ranged from<LOD(L3)—116.51(L11)ng·m L-1 and 0.03(D22)—17.55(D7)ng·m L-1,Whereas,in formula milk,the average concentrations of LMS from 2.73(L3)to 517.66(L14)ng·m L-1,and CMS from<LOD(D3)—405.18(D7)ng·m L-1.(3)The exposure of methylsiloxanes in artificial saliva and formula milk were evaluated by point evaluation method,respectively.Considering that the teats are in contact with both saliva and milk powder during the actual use for infants,the oral exposure of methylsiloxane to saliva and milk powder were comprehensively assessed.The results showed that the total methylsiloxane(MW<1000)exposured to children aged 3—6 months was 694.85?g·kg-1·d-1,which was higher than other exposure pathways,so the oral exposure of methysiloxanes to infants may be the main pathway.Since the ADI value of methyl siloxane is not standard,under the long-term high intake and enrichment of methyl siloxane,the safety of methyl siloxane is still to be further studied.(4)An efficient and sensitive analysis method for methylsiloxanes in fried chicken and fried chips was established by Qu ECh ERS-GC-MS and Qu ECh ERS-GC-MS/MS,respectively.Then methylsiloxanes in 33 fried chicken and 30 fried chips were detected and oral exposure were assessed preliminarily.In fried chickens,the average concentrations for LMS and CMS ranged from 5.92(L3)—99.72(L11)ng·g-1 and 5.68(D4)—262.9(D6)ng·g-1;The total exposure(?MS)was 34.59—112.42 ng·kg-1·d-1(median),and?CMS>?LMS.Methylsiloxanes in the fried chicken may derived from degration of high molecular weight PDMS at high temperature.The average content of LMS in French fries is 0.02(L10)—19.31(L6)ng·g-1,whereas the average content of CMS is 1.11(D4)—66.72(D17)ng·g-1.The difference of?LMS and?CMS between French fries and fried chicken is significant,and Comparing with the fried chicken,it was found that the content of fried chicken was higher than French fries,which may be due to the fact that methyl siloxane is more easily adsorbed to high fat content samples—fried chicken.Total exposure(median)of methylsiloxanes in French fries was 6.84—196.47 ng·kg-1·d-1.At present,the ADI value of methyl siloxane is not standard,and there is no poisoning acute events caused by ingestion of methyl siloxane in fried products,but under the effect of long-term low-toxic intake and richness,whether it would have an adverse effect on human function(especially reproductive system),further researches should be needed. |
PDF Full Text Request