Application Of Microextraction Techniques In Analysis Of Amphetamine-type Drugs

Drug abuse is a long-standing social problem that does harm to human health,family harmony and social stability.In the process of forensic toxicology drug testing,it is important to determine drugs and their major metabolites rapidly and accuratelymethod for determinaton of.However,due to the complex metabolism and toxicological effects of drugs in the human body,and the their concentration can gradually decrease with time prolonging.Therefore,it is necessary to establish an efficient analytical method for determination of toxicants and their main metabolites.The traditional sample pretreatment technologies represented by liquid-liquid extraction technique have the disadvantages of complicated steps,time-consuming and labor-intensive,and a large amount of comsumption of organic solvent,etc.To solve these problems,analytical chemists have developed new sample preparation techniques represented by solid phase microextraction(SPME)and liquid phase microextraction(LPME).SPME and LPME technologies have the advantages of simple operation,integrating sampling,extraction,concentration and sample injection,and can be compatible with analytical instruments such as gas chromatography(GC)and liquid chromatography(LC).In contrast,the former has higher sensitivity and selectivity,while the latter has the advantages of low cost and no memory effect.The abovementioned two techniques can complement each other and can effectively solve the problem of extraction and concentration of many target analytes from biological,environmental and food samples.This study mainly carried out the analysis of amphetamines in biological samples by using fiber SPME and single drop microextraction(SDME)techniques of.The main contents are as following:1.Introductin of the research background and significance of this paper;based on the aformentioned introduction,a more detailed review of the latest developments of SPME and LPME and the latest application of the two technologies in drug analysis in biological samples was made.2.The six kinds of amphetamine-type drugs in urine were detected by SDME under the promotion of electric field.Under optimized conditions,the six target compounds had a good linear relationship in the range of 20～1000 μg/L(r = 0.989～0.997),the detection limit(LOD)can reach 3.2～7.6 μg/L,and the detection of three kinds of spiked urine samples at different concentrations,the recovery rate of amphetamines is 91.6% ～ 111.2%,and the precision is between 2.9% ～ 6.2%.Finally,the developed method was applied to the actual sample inspection and the satisfactory results were obtained.The experimental results prove that the introduction of electric field in the SDME process helps to improve the extraction efficiency.3.Using isobutyl chloroformate(IBCF)as the derivatization reagent,combined with the introduction of electric field strategy,the analytical method of amphetamine(AM)and methamphetamine(MA)in urine was established.Under optimized conditions,the linearrange of this method is 1～2000 μg/L,and the determination coefficient is 0.99(r> 0.99).For the detection of spiked urine samples at three different concentrations,the precision of AM was 5.9 ～ 11.4%,and the recoveries was 84.5% ～ 96.2%.The recoveries of MA are82.7%～96.1%,and the precision is 5.2%～11.8%.The optimized in situ derived EE-SDME-GC method was applied to the actual urine samples of AM and MA abusers,and the effect was obvious.Experiments show that this method can be used for the detection of amphetamines in biological fluids of forensic toxicology.4.After acid oxidation treatment of the multi-wall carbon nanotube(MWCNTs)material,a SPME fiber coating is prepared,and a headspace SPME technique was developed and used to analyze amphetamines in urine.Under optimized conditions,LOD and limit of quantification(LOQ)are in the range of 0.2～1.3 μg/L and 0.7～4.3 μg/L,respectively,and the calibration curve is linear in the range of 0.5～1000 μg/L(r = 0.963～0.999).Three kinds of spiked urine samples with different concentrations were evaluated.The recoveries of amphetamines were 88%～107%,and RSD was less than 5.4%.Three kinds of spiked urine samples with different concentrations were tested.The recoveries of amphetamines were88%～107%,and RSD was less than 5.4%.Comparing the extraction efficiencies of PDMS,MWCNTs and MWCNTs-COOH coatings,the following conclusions can be drawn: the MWCNTs-COOH coating developed in this study exhibites the highest extraction efficiencies and showed high thermal stability,which can meet laboratory amphetamine drug testing.