Screening,Migration And Safety Assessment Of Risk Substances In Food Contact Rubber Materials And Products

Due to complex production process and ingredients,some risk substances in these food contact rubber materials and products migrate potentially into foods,which bring a negative impact on food safety and quality.In this study,food contact rubber materials and products were taken as the research objects.The sources of potassium permanganate consumption of rubber products,the non-targeted screening and safety assessment of rubber liners,and the selection of the fatty food simulant for food contact rubber was studied.At the same time,it provides basic data for the revision of GB 4806.11-2016 national food safety standard for food contact rubber materials and products.The specific studies were as:(1)The potassium permanganate consumption of 30 kinds of food contact rubber materials and products was analyzed,and 8 of them exceeded the standard limit(10 mg/kg).The main materials of rubber products with excessive consumption of potassium permanganate were determined by infrared spectrum analysis.Headspace gas chromatography-mass spectrometry(HS-GC-MS),gas chromatography-quadrupole time-of-flight-mass spectrometry(GC-QTOFMS)and liquid chromatography-quadrupole time-of-flight-mass spectrometry(LC-QTOF-MS)were used to analyze the migrants.A total of 30 compounds were screened out,which were mainly intentionally added substance(such as vulcanization accelerator,antioxidant and scorch inhibitor,etc.)and non-intentionally added substance(such as degradation products of vulcanization accelerator,etc.).Three screening methods can effectively identify the migrants,and it is preliminarily determined that the possible sources of potassium permanganate consumption are these small molecular compounds containing reducing functional groups.(2)The raw milk extruded by cow’s teat is in direct contact with rubber liners.Therefore,the safety of food contact rubber liners in milking systems directly affects the safety of raw milk.The results showed that infrared spectrum analysis identified 10 rubber liners as nitrile and styrene butadiene rubber.HS-GC-MS,GC-MS and LC-QTOF-MS were used to screen and analyze the migrants.A total of 60 compounds were identified through non-targeted screening,including additives(vulcanization accelerator,antioxidant,antioxidant,etc.)and their degradation products used in the processing of food contact rubber materials and products.Toxicological threshold of concern(TTC)method combined with Cramer decision tree was used for risk assessment.Thirty-five compounds were classified as Cramer III(high toxicity)compounds,which may bring potential hazards to human health.More attention should be paid to ensure the safe use of rubber liner.(3)A method was developed for the determination of the migration amounts of 5 compounds,i.e.aniline,N-methylaniline,1,3-diphenylguanidine,2-mercaptobenzothiazole and benzothiazole in food contact rubber liners by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The results showed that the contribution of KMn O4 consumption in rubber liner(L1)from these five compounds in soaking solution was 37.20%.Other compounds containing reducing functional groups may be oxidized by potassium permanganate.This method was used to detect the migration amounts of 5 compounds in 10 kinds of food contact rubber liners under the three conditions(40 ℃ for 10 min,40 ℃ for 30 min and 40 ℃ for 120 min)and the same rubber liner used 60 times(40 ℃ for 10 min).According to the migration results,5 compounds was detected in all liners,and the migration amounts of 1,3-diphenylguanidine and 2-mercaptobenzothiazole were within the limit ranges.The detection of benzothiazole needs attention.The migration amounts of aniline and Nmethylaniline were higher than its migration limit(0.01 mg/kg),and the generation of aniline and N-methylaniline must be controlled by improving the formulation or the process.(4)The purpose is to study the applicability of 50% ethanol as the fatty food simulant for food contact rubber.And the results of this study provide data support for the revision of the standard of food contact rubber in China.This paper took the positive rubber samples containing 1,4-diphenyl-1,3-butadiene(DPBD)as the research object.The migration of DPBD from the positive rubber samples to real foods,food simulants(50% ethanol and olive oil)and substitute solvent(95% ethanol)were respectively determined and compared by gas chromatograph-triple quadrupole tandem mass spectrometry(GC-MS/MS).The results showed that the setting of fatty food simulant(50% ethanol)was not completely applicable in the current standard of food contact rubber.It is recommended to select olive oil as the fatty food simulant.It is not recommended to correct the results of olive oil while the rubber comes into contact with hotpot condiment or butter.It is recommended to correct the results of olive oil while the rubber comes into contact with ham sausage or luncheon meat.It is not recommended to correct the results of 50% ethanol solution while the rubber comes into contact with ham sausage or luncheon meat.95% ethanol can be used as the substitute solvent for nitrile butadiene rubber(NBR),but it is not recommended for ethylene propylene diene monomer rubber(EPDM).