OBJECTIVES: Tiletamine, a veterinary anesthetic, has emerged as a novel psychoactive substance and has been abused in many parts of the world, causing great harm to public health. However, the sensitivity of existing detection methods cannot meet the needs of forensic practice. This study aims to establish an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of tiletamine and its metabolite desethyltiletamine in human biological samples, and to verify its applicability in forensic practice. METHODS: SKF_525A was used as the internal standard. Biological samples were extracted with acetonitrile containing 1 ng/mL SKF_525A, vortexed for 10 min, ultrasonicated for 20 min, centrifuged at 10 000 r/min for 10 min, and 500 μL of the supernatant was filtered through a 0.22 μm membrane. Analyses were performed using an ACQUITY UPLC H-Class PLUS system and an XEVO TQ-S Micro triple quadrupole mass spectrometer. An ACQUITY UPLC^® BEH C18 (1.7 µm, 2.1 mm×100 mm) column at a flow rate of 0.3 mL/min was used, and four mobile phase systems were tested to optimize separation. Detection used positive electrospray ionization (ESI+) in multiple reaction monitoring (MRM) mode, with quantifier ion transitions of mass to charge 224.043→179.016 for tiletamine and mass to charge 196.08→151.06 for desethyltiletamine. Calibration curves were established over 0.1-200 ng/mL in spiked blood samples. The linear range, limit of detection (LOD), and limit of quantification (LOQ) were determined. Low (5 ng/mL), medium (20 ng/mL), and high (100 ng/mL) concentrations of tiletamine were spiked into blood, liver, and kidney to evaluate precision, accuracy, matrix effect, recovery, and stability. Finally, actual forensic case samples were tested to validate applicability. RESULTS: The established UPLC-MS/MS method achieved simultaneous detection of tiletamine and desethyltiletamine in human biological samples, with retention times of 3.42 min and 2.82 min, respectively. Using mobile phase A (20 mmol/L ammonium acetate and 0.1% formic acid in water) and mobile phase B (acetonitrile) produced the best separation. In blood, tiletamine showed good linearity from 0.1-200 ng/mL (r=0.992, R²=0.983), LOD 0.03 ng/mL, LOQ 0.1 ng/mL, recovery 92%-107%, and matrix effect 71%-99%. In liver and kidney, recoveries were 91%-98% and 93%-104%, and matrix effects were 69%-96% and 72%-100%, respectively. Intra- and inter-day precision [expressed as relative standard deviation (RSD)] and accuracy [expressed as relative error (RE)] were within 15%, and samples were stable at -20 ℃. Tiletamine was detected in actual case samples at 0.37 μg/mL (blood), 0.15 μg/g (liver), 0.11 μg/g (kidney) in case 1, and 8.75 ng/mL (blood) in case 2; desethyltiletamine was also detected in blood. CONCLUSIONS The UPLC-MS/MS method is efficient, accurate, and sensitive, and is suitable for detecting tiletamine and desethyltiletamine in human biological samples.
Tandem Mass Spectrometry/methods* ; Humans ; Chromatography, High Pressure Liquid/methods* ; Substance Abuse Detection/methods* ; Liquid Chromatography-Mass Spectrometry

In recent years, the types and quantities of fentanyl analogs have increased rapidly. It has become a hotspot in the illicit drug control field of how to quickly identify novel fentanyl analogs and to shorten the blank regulatory period. At present, the identification methods of fentanyl analogs that have been developed mostly rely on reference materials to target fentanyl analogs or their metabolites with known chemical structures, but these methods face challenges when analyzing new compounds with unknown structures. In recent years, emerging machine learning technology can quickly and automatically extract valuable features from massive data, which provides inspiration for the non-targeted screening of fentanyl analogs. For example, the wide application of instruments like Raman spectroscopy, nuclear magnetic resonance spectroscopy, high resolution mass spectrometry, and other instruments can maximize the mining of the characteristic data related to fentanyl analogs in samples. Combining this data with an appropriate machine learning model, researchers may create a variety of high-performance non-targeted fentanyl identification methods. This paper reviews the recent research on the application of machine learning assisted non-targeted screening strategy for the identification of fentanyl analogs, and looks forward to the future development trend in this field.
Fentanyl ; Substance Abuse Detection/methods* ; Mass Spectrometry/methods* ; Illicit Drugs/analysis*

OBJECTIVES: To establish a combined high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) method to detect the synthetic cannabinoid CUMYL-PEGACLONE in e-cigarette oil and hair. METHODS: HPLC-MS/MS and GC-MS were used to establish the detection method of CUMYL-PEGACLONE, and the hair of drug-involved persons and the seized e-cigarette oil were detected. RESULTS: The main mass spectrometry characteristic ions m/z of CUMYL-PEGACLONE measured by GC-MS were 91, 179, 197, 254 and 372. CUMYL-PEGACLONE had a good linear relationship in the mass concentration range of 2-50 ng/mL, and the linear correlation coefficient (r) was greater than 0.99. The limit of detection (LOD) of CUMYL-PEGACLONE in hair was 0.01 ng/mg, and the limit of quantitation (LOQ) was 0.02 ng/mg. The LOD of CUMYL-PEGACLONE in e-cigarette oil was 1 ng/mg, and the LOQ was 2 ng/mg. The average recoveries of CUMYL-PEGACLONE under the attempt at high, intermediate and low levels in blank human hair and e-cigarette oil matrix were 98.2%-132.4% and 93.5%-110.6%, and the intraday and intraday precision were 1.2%-12.9% and 0.7%-2.9%. CUMYL-PEGACLONE was detected in the hair of 15 drug-involved persons. Except for 1 person who was lower than LOQ, the concentration of CUMYL-PEGACLONE in the hair of other 14 persons was 0.035-0.563 ng/mg. The mass fraction of CUMYL-PEGACLONE in 2 e-cigarette oil were 0.17% and 0.21%, respectively. CONCLUSIONS The established HPLC-MS/MS and GC-MS methods are applied to the detection of HPLC-MS/MS in drug-related cases, which provides strong evidence support for the handling authority to quickly investigate these cases, and also provides a reference for the identification of such substances in future.
Humans ; Illicit Drugs/analysis* ; Tandem Mass Spectrometry ; Electronic Nicotine Delivery Systems ; Cannabinoids ; Hair/chemistry* ; Limit of Detection ; Substance Abuse Detection/methods*

Drug problem is a major social and public security problem in the world. Drug abuse poses a great threat to economic development, social stability and public health. In recent years, synthetic drugs represented by methamphetamine have surpassed traditional drugs such as morphine, heroin, ketamine and become one of the most abused drugs in the world. In order to solve the problem of drug abuse, it is of great theoretical value and practical significance to carry out all-round and multi-level scientific research on drug-related issues. Based on the current situation of drug abuse, this article reviews research progresses on the epidemiology of methamphetamine abuse, the monitoring technology, the basic researches on toxicity damage, the withdrawal drug screening, the related clinical comorbidity and the testing technologies, comprehensively presenting the development trend of methamphetamine abuse related issues.
Amphetamine-Related Disorders/epidemiology* ; Heroin ; Humans ; Illicit Drugs ; Methamphetamine/adverse effects* ; Substance Abuse Detection

Amphetamines are chemical synthetic drugs that are becoming increasingly popular in China. As a common sample in the inspection of poisons, hair has the advantages of easy storage, good stability, and long detection time compared with traditional human body fluid samples （blood, urine）, thus possesses an unique application value in the field of forensic toxicology analysis. By now, methods for detecting amphetamines in human hair have been widely used, and validity of the results has been recognized and adopted by the court. This paper reviews domestic and foreign research progress of the detection of amphetamines in hair samples, including the pretreatment and analytic methods.
Amphetamines/analysis* ; China ; Forensic Toxicology ; Hair/chemistry* ; Humans ; Substance Abuse Detection

Methamphetamine （MAMP） is a kind of amphetamine-type stimulants （ATS） which contains one chiral carbon atom in its structure. Therefore a pair of enantiomers, S-（+）-MAMP and R-（-）-MAMP exist. R type and S type methamphetamines possess similar physicochemical properties, but has largely different pharmacological and toxic effects. S-（+）-MAMP is the main component of addictive drug "Ice" at present, seriously affecting human health and public safety. The separation analysis and mechanism of toxic effects discussions on MAMP are the current research focuses. This paper reviews the research progress of separation analysis methods and toxic effects of methamphetamine enantiomers to provide reference for forensic study and forensic practice.
Central Nervous System Stimulants ; Humans ; Methamphetamine/chemistry* ; Stereoisomerism ; Substance Abuse Detection

Objective To establish accurate and rapid methods to identify four new synthetic cannabinoids （JWH-203, JWH-122, 5F-APINACA and AB-CHMINACA） in blood samples. Methods The whole blood samples were extracted by acetonitrile and methanol, screened by gas chromatography-mass spectrometry （GC-MS） then confirmed by liquid chromatography-tandem mass spectrometry （LC-MS/MS） method, and multiple reaction monitoring （MRM） mode was used for quantitative analysis. Results The GC-MS method needed 21 min to complete the analysis, while the LC-MS/MS method needed 5 min. The AB-CHMINACA, JWH-203, 5F-APINACA and JWH-122 all used quasi molecular ion peak as a parent ion. The precursor-product ion combinations were m/z 357.4→312.2, m/z 340.2→125.0, m/z 384.1→135.1 and m/z 356.4→169.2. The four synthetic cannabinoids in blood samples had good linearity in the 1-250 ng/mL mass concentration range （r>0.99）. The limits of detection （LODs） were in the range of 0.1-0.5 ng/mL, the recovery rate was 85.4%-95.2%, the RSD less than 10.0%, and the matrix effect was 80.3%-92.8%. Conclusion The GC-MS and LC-MS/MS chromatographic behaviors and mass spectrometry analysis information of four synthetic cannabinoids were obtained in this study, and the possible causes of differences in chromatographic behaviors were discussed preliminarily. Therefore this study has a suggestive effect on judging the development trend of synthetic cannabinoids. This method can be used for rapid identification of four synthetic cannabinoids in blood, which can provide reference for identification of new synthetic cannabinoids when they are proliferating at present.
Blood Chemical Analysis/methods* ; Cannabinoids/blood* ; Chromatography, Liquid ; Humans ; Limit of Detection ; Substance Abuse Detection/methods* ; Tandem Mass Spectrometry

OBJECTIVES: To identify the new designer drugs which are totally unknown and not in the routine testing list by the technologies such as high-resolution mass spectrometry in drug facilitated sexual assault, in order to solve the problem in actual cases. METHODS: The milky fluid from an actual case was extracted and analyzed using LC-QE, ¹H-NMR and GC-MS, respectively. The accurate masses and cluster ions isotope patterns of unknown compound were obtained by LC-QE. The molecular formula was confirmed as C₁₆H₁₂C₂N₂O based on the protons number of ¹H-NMR. The isomers diclazepam and 4-chlorodiazepam were separated and detected with GC-MS. RESULTS: The new designer benzodiazepine as diclazepam in the milky fluid was identified. The results provided direct evidence for the investigation and qualitative analysis of such cases. CONCLUSIONS The combined application of various methods, including LC-QE, ¹H-NMR and GC-MS, can be used to detect unknown new psychoactive substances.
Benzodiazepines/chemistry* ; Benzodiazepinones ; Chromatography, Liquid/methods* ; Designer Drugs/chemistry* ; Female ; Gas Chromatography-Mass Spectrometry/methods* ; Humans ; Male ; Mass Spectrometry/methods* ; Sex Offenses ; Substance Abuse Detection/methods* ; Toxicology/methods*

Objective: To explore the reasons and factors associated with new psychoactive substances abuse among patients with access to methadone maintenance treatment (MMT). Methods: A well-developed questionnaire and urine tests were used to collect information about demographic characteristics, condition of MMT and drug abuse, family and social support of MMT clients. A 1∶1 matched case-control study was conducted, and conditional logistic regression model was used to identify factors associated with new psychoactive substances abuse. Results: A total of 212 (106 pairs) clients receiving MMT were recruited, and most of them were males (78.3%, 166/212), married or cohabitant (48.6%, 103/212) and unemployed (63.2%, 134/212). The average age of the clients was (45.1±7.2) years. The main types of abused new psychoactive substances were benzodiazepine (62.3%, 66/106) and methamphetamine (39.6%, 42/106). The proportion of abusing multi new psychoactive substances was 8.5% (9/106). Results from multivariate conditional logistic regression analysis indicated that using opioid drug during the past 6 months of MMT treatment might increase the risk of abusing new psychoactive substances (OR=3.25, 95%CI: 1.35-7.79), benzodiazepine (OR=3.25, 95%CI: 1.11- 9.47) and methamphetamine (OR=13.31, 95%CI: 1.12-158.01). Moreover, MMT for more than9 years reduced the risk of abuse of new psychoactive substances (OR=0.03, 95%CI: 0.01-0.21), benzodiazepine (OR=0.02, 95%CI: 0.00-0.36) and methamphetamine (OR=0.02, 95%CI: 0.00-0.69). Conclusion: Less new psychoactive substances abuse might be associated with longer duration of MMT treatment. And inappropriate support from family and friends might increase the risk of abusing new psychoactive substances in MMT clients, especially in clients who used opioid.
Adult ; Case-Control Studies ; China/epidemiology* ; Drug Users/statistics & numerical data* ; Humans ; Logistic Models ; Male ; Methadone/therapeutic use* ; Methamphetamine ; Middle Aged ; Opiate Substitution Treatment ; Prevalence ; Psychotropic Drugs/adverse effects* ; Substance Abuse Detection/statistics & numerical data* ; Substance Abuse Treatment Centers ; Substance-Related Disorders/epidemiology* ; Surveys and Questionnaires

OBJECTIVES: To infer the frequency of dosage and medication history investigate of the victims in drug facilitated cases by the segmental analysis of clonazepam in hair. METHODS: Freezing milling under liquid nitrogen environment combined with ultrasonic bath was used as sample pretreatment in this study, and liquid chromatography-tandem mass spectrometry was used for the segmental analysis of the hair samples collected from 6 victims in different cases. The concentrations of clonazepam and 7-aminoclonazepam were detected in each hair section. RESULTS: Clonazepam and its metabolite 7-aminoclonazepam were detected in parts of hair sections from the 6 victims. The occurrence time of drug peak concentration was consistent with the intake timing provided by victims. CONCLUSIONS Segmental analysis of hair can provide the information of frequency of dosage and intake timing, which shows an unique evidential value in drug facilitated crimes.
Adult ; Chromatography, Liquid ; Clonazepam/analysis* ; Crime ; Forensic Medicine/methods* ; Forensic Toxicology ; Hair/chemistry* ; Humans ; Mass Spectrometry ; Spectrometry, Mass, Electrospray Ionization ; Substance Abuse Detection/methods* ; Ultrasonics