Study On The Application Of Microextraction Technology In Hair Drug Analysis

Social stability is an important foundation of economic development.Drug abuse will have a serious impact on social stability.The public security and criminal cases caused by drug abuse increase year by year,causing many social problems.According to the results of the 2018 China drug situation report,by the end of 2018,there were 2.404 million drug users in China,of which a large proportion was new drugs,accounting for 56.1% of the total number of drug users in China(about 1.35 million),and new drugs(methamphetamine)had become the most abused drugs in China.It is the frontier research field of analytical chemistry to build a new method of complex sample pretreatment which is fast,economic and environment-friendly.It is of great significance to the efficient and robust analysis of hair drugs.In this paper,two methods(dispersive liquid microextraction and solid-phase microextraction)were used in the pretreatment of hair samples.The effects of different microextraction techniques on the pretreatment of hair samples were discussed.The drugs in hair samples were analyzed and identified by GC-MS.The main contents include the following four chapters:The first chapter introduces the development of drug situation at home and abroad,and investigates the analytical methods of drug detection in the body of the addicts.Based on the characteristics of hair samples,which are easy to be taken,carried,stored for a long time and metabolized slowly,the pretreatment process of hair samples and the application of microextraction technology in drug analysis are summarized.Based on the above discussion,this paper puts forward the idea and research content.In the second chapter,the dispersive liquid-liquid microextraction was applied to the pretreatment of hair samples,and the methamphetamine and ketamine in hair were analyzed qualitatively and quantitatively by GC-MS.The types of detergents,digesters,extractants,dispersants,extractant dosage and injection conditions were optimized.The results show that this method has good enrichment and purification performance for chloramine and methamphetamine in hair samples.The content of ketamine in hair was determined.Under the basic condition of 1 mol/L Na OH,200 μL saturated potassium chloride solution was added to the analyte.The dispersing agent was methanol,and the extracting agent was 100 μL trichloromethane.The linear range of the analytical method were 2.5 ng/mg-50 ng/mg,the detection limit was 0.5 ng/mg,the recovery of standard addition was 85.1%-119.6%,and the RSD was 5.4%(n=5).The content of methamphetamine in hair was determined.Under the basic condition of 1 mol/L Na OH,200 μL saturated potassium chloride solution was added to the analyte,the dispersant was methanol,and the extractant was 100 μL trichloromethane.After extraction,50 μL trifluoroacetic anhydride was added to the clear liquid,which was placed at room temperature for 30 minutes to carry out the derivatization reaction.The linear range of analysis method were 0.5 ng/mg-50 ng/mg,and the detection limit was 0.1 ng/mg.The recovery of standard addition was 86.9%-125.8%.In this paper,DLLME technology,which consumes less organic solvent,is more environmentally friendly and convenient,and integrates extraction,enrichment and sample injection.The method combined with GC-MS can be applied to the rapid and robust analysis of methamphetamine in hair.In the third chapter,an ionic liquid solid phase microextraction(SPME)coating based on stainless steel wire was prepared by sol-gel technology.The thermal stability,solvent resistance and extraction ability of the coatings were investigated.The SPME-GC-MS method for the determination of methamphetamine in hair samples was established by optimizing the conditions of SPME-GC-MS.The results showed that the stainless steel wire ionic liquid coating based on sol-gel method effectively enhanced the extraction efficiency of methamphetamine and ketamine in hair drugs.The content of ketamine in hair was determined by headspace extraction in 1 mol/L Na OH solution containing 2 g sodium chloride under the optimized condition of SPME.The linear range of the analytical method were 1 ng/mg-10 ng/mg,the recovery was 80.1%-126%,and the relative standard deviation(n=3)was 5.0%.For the determination of methamphetamine in hair,the linear range of the analytical method were 0.25 ng/mg-10 ng/mg,the recovery rate is 90.0%-108%,and the relative standard deviation(n=3)is 9.5%.Compared with liquid-phase microextraction,solid-phase microextraction is more environmentally friendly in the sample pretreatment process of hair drug analysis.In the fourth chapter,based on the good conjugated structure of the pyrazolophos pyridine heterocyclic compounds,the sol-gel technology was applied to the self-made solid phase microextraction probe coating,which was applied to the pretreatment process of hair samples,and then the qualitative and quantitative analysis of the drugs in hair was carried out by gas chromatography-mass spectrometry.The extraction temperature,extraction time,salt content and injection conditions were optimized.The temperature resistance,solvent resistance and extraction selectivity of bipyrazolopyridine solid-phase microextraction probe were investigated.The new material solid-phase microextraction device has good extraction performance for aniline and alcohol compounds.The content of methamphetamine in hair was determined.The results showed that under the optimized extraction conditions,the linear range of the analytical method was 0.5 ng/mg-10 ng/mg,the recovery was 86.2%-133%,and the relative standard deviation(n = 3)was 3.9%.The established analytical method was used to quantitatively confirm the positive methamphetamine hair samples.The results showed that the linear range was 0.01 ?g/mg-0.3 ?g/mg,the relative standard deviation(n=3)was 4.4%,and the recovery rate was 91.0%-105%.