Simultaneous Determination of Methamphetamine and Its Isomer N-Isopropylbenzylamine in Forensic Samples by Using a Modified LC-ESI-MS/MS Method

Abstract

Accurate identification and quantification of methamphetamine (MA) and its related substances are essential for the investigation and fair trial of drug offenses. In this study, a modified LC-ESI-MS/MS method for the simultaneous determination of MA and its isomer N-isopropylbenzylamine (N-IBA) in forensic samples was developed and validated. Optimum chromatographic separation of the target analytes was achieved on an Agilent Poroshell 120 SB-C18 column ( 4.6 × 100 mm, 2.7 μm) at 40°C with isocratic elution at the flow rate of 0.40 mL/min. The mobile phase was acetonitrile and 20 mM ammonium acetate solution containing 0.1% formic acid (80 : 20, v / v ). Positive ESI-MS/MS detection was performed in multiple reaction monitoring (MRM) mode to identify and quantify the target analytes. Method validation showed excellent linearity in the range of 0.51 ng/mL~51 ng/mL for MA and N-IBA. The low limit of detection (LLOD) and low limit of quantification (LLOQ) reached 0.1 ng/mL and 0.3 ng/mL for both analytes. The method showed a satisfactory accuracy with an inter- and intraday-relative error (RE) <20%, and a precision of inter- and intraday relative standard deviation (RSD) less than 15%. The validated method was successfully applied in real forensic samples and resulted in the detection of MA and N-IBA in 8 suspected samples in drug cases that only deemed MA positive using our previous routine screening procedure, which avoided the misidentification of N-IBA as MA.

Interpol Review of Drug Analysis 2019-2022

“…2019 Analysis of aerosolized methylamphetamine from e-cigarettes using SPME-DART-HRMS and SPME-GC-MS [ 162 ]; fluorescent nanosensor for detection of methylamphetamine [ 163 ]; supercritical fluid chromatography-tandem mass spectrometry method could be a powerful analytical tool for methylamphetamine impurity profiling [ 164 ]; 2020 a novel fluorescent nanosensor based on graphene quantum dots embedded within molecularly imprinted polymer was developed for detection and determination of methylamphetamine [ 165 ]; chemosensor for detection of MA [ 166 ]; determination of the stereoisomeric distribution of R-(−)- and S-(+)-MA using HPLC-MS and GC-MS [ 167 ]; use of IRMS alongside conventional chemical profiling techniques to investigate whether methylamphetamine samples of differing P2P origins can be distinguished through drug profiling [ 168 ]; smartphone-based device for rapid on-site MA detection [ 169 ]; fluorescent drug detection device based on LED induction (FD-LED) for MA [ 170 ]; NIR-PLS quantitative modelfor seven adulterants with MA purity ranging from 10% to 100%, [ 171 ]; fluorescent nanosensor for detection of MA [ 172 ]; 2021 fluorescence resonance energy transfer-thermal lens spectrometry (FRET-TLS) for the determination of MA [ 173 ]; H-1 NMR method for discrimination of the enantiomers of MA from ephedrine and pseudoephedrine using chiral solvents [ 174 ]; review of the optical and electrochemical sensors used to date for MA detection in seized and biological samples [ 175 ]; development of an IMS method to detect MA using pyridine as a dopant in the presence of nicotine [ 176 ]; development and validation of a modified LC-ESI-MS/MS method for the simultaneous determination of MA and its isomer N-isopropylbenzylamine (N-IBA) in forensic samples [ 177 ]; SERS method for detection of MA [ 178 , 179 ]; investigation of the reaction mechanisms of three different synthesis methods (Nagai, Hypo, and Moscow) for MA [ 180 ]; establishment of likelihood ration models to evaluate the cause of MA contamination resulting from either use or clandestine manufacturing [ 181 ]; 2022 study of forensic markers of 1-phenyl-2-propanone synthetic pathways for identification of precoursors to methamphetamine [ 182 ]; impurity profiling of MA synthesized from alpha-phenylacetoacetonitrile (APAAN) including the identification of five new impurities and two previously identified impurities [ 183 ]; investigation of the use of stable isotope ratio mass spectrometry (IRMS) to determine the precursor and precursor origin of MA drug samples [ 184 ]; development of an electrochemical detection technique to determine the residual methamphetamine contamination on household surfaces [ 1...…”

Comprehensive Analysis of Analogues of Amine-Related Psychoactive Substances Using Femtosecond Laser Ionization Mass Spectrometry

“…The most popular method for achieving this is gas chromatography combined with mass spectrometry (GC–MS). The sample can be separated by liquid chromatography (LC) and measured by electrospray ionization-MS × MS (the isomers were differentiated by the statistical/chemometric analysis of the fragment ions). − However, the separation resolution of LC is sometimes insufficient and is not suitable for comprehensive analysis of unknown samples since the target analyte should be decided before measuring the sample.…”