Rapid Detection Of Drugs In Urine Based On Arc Discharge Mass Spectrometry

Nowadays,illicit drug abuse is a serious social problem.There are estimated 200 million illicit drug users all over the world.Drug dealers could make huge profits by carrying out the manufacture and dealing of illegal drugs,taking advantage of the addictive hallucinogenic effects and other side effects of illicit drugs,which has a significant impact on social security,people’s safety as well as the health of addicts and their social life.Therefore,establishing a rapid detection and analysis method which could be suitable for both qualitative and quantitative analysis of illicit drugs in environmental waters,beverages and body fluids of suspects has a positive effect on the rapid screening of drug users as well as drug prevention.In ambient ionization mass spectrometry,low-temperature plasma could be used as the ion source and ions of analytes could be generated,detected and analyzed by mass spectrometer.In this dissertation,an arc discharge ion source was designed and combined with a Quadrupole Time-of-Flight mass spectrometry(Q-TOF MS)to quantitatively analyze six illicit drugs including furanylfentanyl,methamphetamine,tetrahydrocannabinol,ketamine,phenazepam and methadone.1.The auxiliary air flow,auxiliary heating and arc discharge devices of arc discharge ion source is assembled and built together.The experimental parameters such as distance,flow rate,addition amount,discharge time and temperature are optimized,so that the stability,signal intensity and ionization efficiency of quantitative analysis and detection are at optimum.2.The quantitative analysis of six illicit drugs was carried out by assembling an arc discharge ion source.The quantitative limit and detection limit were detected by using methanol and deionized water as solvents.Then the standard curve relationship between drug concentration and signal intensity was measured in the concentration range,and the linear correlation was greater than 0.998.Finally,six real samples,such as Great Wall Five-star Red wine,Great Wall Dry Red wine,Sangou Laojiao liquor,Coke,fruit juice,pond water,were used to simulate the rapid detection on site,and the recovery rate was calculated.The final results were in the range of 90%and 110%,indicating that the method has the advantages of high sensitivity,good anti-ion inhibition and high accuracy.3.Proton affinity(PA)for specific electron-rich sites in the molecular structure was inferred from theoretical calculations to determine the most likely proton binding site in the parent ion.Afterwards,optimal MS/MS and energy conditions were established and fragment ions were used to infer to the parent ion fragmentation process as well as the daughter ion fragment structure.4.Five solvents,including artificial urine and real urine,were used for multiplexed detection analysis of six illicit drugs,and four temperatures of 100 ℃,150 ℃,175 ℃,and 200 ℃ were selected for mass spectrometry detection,and the mass spectral signal peaks of five drugs could be clearly identified in the mass spectrometry.The five drugs were quantitatively analyzed in real urine.The linear curve analysis was performed using artificial urine(containing creatinine)and artificial urine(excluding creatinine)as standard solutions.The linear correlation coefficients were all greater than 0.998.The matrix effects of creatinine and urea in urine were analyzed.The recovery rate of standard addition in urine was calculated.The results were in the range of 90%and 110% as well,which proved that the arc discharge ion source had high sensitivity,good selectivity,high repeatability and good accuracy.This dissertation establishes an arc discharge mass spectrometry method with rapid detection,direct analysis,high sensitivity and good environmental selectivity,which has great potential for the rapid detection of illicit drugs in the field.