Environmental Exposure And High-throughput Screening Techniques For Halogenated Organic Contaminants In Animal-derived Foods

Halogenated organic contaminants(HOCs)are a kind of organic compounds containing halogens in their molecular structures,which are widely distributed in ecological environments.In December 2022,the Ministry of Ecology and Environment issued the "Key Controlled Emerging Contaminants List(2023 Edition)",which contained4 categories(14 types)of emerging contaminants that were restricted or banned,including various HOCs.The environmental pollution level,environmental behavior and toxicological properties of HOCs have become one of the hot topics in the current international environmental and scientific research.Over the past few decades,the widespread use of HOCs in fields such as textiles,food packaging,and electronic products has led to an increasing level of environmental pollution.HOCs have been widely detected in various environmental media such as soil,air,water bodies,sediments,organisms,humans,and food.Emerging HOCs,as substitutes for traditional HOCs,have also exacerbated their environmental pollution levels due to the increase in industrial production and usage.HOCs have characteristics such as persistence,long-range migration,bioaccumulation,and potential toxicity.Dietary exposure is an important pathway for human intake of HOCs,and the potential health risks caused by HOCs have become a focus of research both domestically and internationally.It is crucial to conduct comprehensive screening for complex biological samples,including structural confirmation of unknown HOCs and quantitative analysis of known HOCs,in order to accurately understand the multi environmental medium occurrence characteristics of HOCs,assess the potential ecological and human health risks,and ultimately implement reasonable management and control policies.The non targeted screening technology based on high-resolution mass spectrometry can theoretically achieve the simultaneous determination of multiple analytes in environmental samples.However,the matrix of biological samples is complex,and preserving more information of the analyte while removing interfering matrix is a prerequisite for achieving high-resolution screening.This article uses chickens as a model to screen the bioaccumulation and transport characteristics of various brominated bisphenol A pollutants in the surrounding environment of brominated flame retardants factories;And based on high-resolution mass spectrometry,a high-throughput screening technology was developed for analyzing three new HOCs pollutants(halogenated carbazole,bromophenol,and tetrabromobisphenol A)with significant polarity differences in multiple types of animal derived foods.Specifically,it includes:(1)In response to the environmental issues of site pollution,this article investigates for the first time the impact of pollution caused by brominated flame retardant chemical plants on surrounding organisms.The main research subjects are hexabromocyclododecane(HBCD)and tetrabromobisphenol A(TBBPA)related substances.A micro experimental base was set up in a farmhouse about 1 kilometer away from the chemical plant,with domestic chickens as the experimental subjects to explore the enrichment and migration characteristics of HOCs in organisms caused by pollution sources in the production area.Research has found that high lipophilic HBCD(mainly α-HBCD)exhibits significant bioaccumulation in animals.Secondly,the enrichment ability of brominated phenol bilaterals in organisms is strong,while the bioaccumulation ability of brominated phenol bilaterals is relatively low.Moreover,the concentrations of HOCs pollutants are significantly different in different organ tissues,and significant gender differences are also found in some chicken tissues.Digestive absorption and fecal excretion are important pathways for the transfer of HOCs pollutants in chickens.Maternal transfer of HOCs pollutants has been observed in the maternal ovaries and offspring tissues,which may have adverse effects on the normal development of embryos.The results of this study will provide data support for further research on the occurrence characteristics and food chain transmission patterns of halogenated pollutants in animal derived foods,and provide methodological support for the accurate implementation of environmental health risk assessment.(2)In view of the problems in the pretreatment technology of complex samples,this paper established a high-throughput screening strategy based on thin-layer chromatography purification technology and high-resolution mass spectrometry detection technology for the simultaneous detection of target and non-target HOCs in animal-derived foods.This method has the advantages of simplicity,solvent saving,high purification efficiency,high sensitivity,high recovery and precision,and small matrix effect.In addition,compared with the traditional purification procedure,the purification method combining physical freezing and thin layer chromatography has significantly improved the removal efficiency of macromolecular proteins,pigments and lipids in complex animal-derived samples.This method has been successfully applied to the detection of actual samples,and targeted analysis of 16 HOCs in nine kinds of animal-derived foods,including carbazole,bromophenol,tetrabromobisphenol A/S and their analogues.In addition,other HOCs in animal-derived samples,including hexabromocyclododecane,mono-bromo bisphenol A,dibromo-bisphenol-A monoallyl ether,suspected 1,3,6-tribromocarzole and other unknown HOCs with recommended molecular formula,were qualitatively and semi-quantitatively analyzed through suspicious and non-targeted screening of high-resolution mass spectrometry.The results show that this method has important potential for further exploring the degradation and transformation products of HOCs pollutants in animalderived foods.