Chiral analysis of amphetamine‐type stimulants using reversed‐polarity capillary electrophoresis/positive ion electrospray ionization tandem mass spectrometry

Abstract

Reversed-polarity (RP) capillary electrophoresis/positive ion electrospray ionization mass spectrometry (CE-ESI+ MS) and tandem mass spectrometry (MS/MS) were utilized for simultaneous chiral separation of nine amphetamine-type stimulants (ATS) (dl-norephedrine, dl-norpseudoephedrine, dl-ephedrine, dl-pseudoephedrine, dl-amphetamine, dl-methamphetamine, dl-methylenedioxyamphetamine, dl-methylenedioxymethamphetamine, and dl-methylenedioxyethylamphetamine). Using highly sulfated gamma-cyclodextrin (SU(XIII)-gamma-CD) as a chiral selector, the nine ATS were completely separated within 50 min. The migrated ATS-CD complex was dissociated at the ESI interface, and only ATS molecules went into the MS detector so that all 18 individual enantiomers were identified by their mass spectra. The detection limit of MS/MS was 10 times more sensitive than those for single MS. Seized d-methamphetamine hydrochloride samples dissolved at high concentration (20 mg/mL) were analyzed. Impurities originating in the precursor such as l-ephedrine and d-pseudoephedrine were detected and identified by tandem mass spectra.

Simultaneous Chiral Analysis of Methamphetamine and Related Compounds by Capillary Electrophoresis/Mass Spectrometry Using Anionic Cyclodextrin

“…The resolution of enantiomers of MA was 5.2. This resolution was similar to that in a report of Iwata et al 15 However, the total analysis time with this concentration was nearly 40 min. Because reducing the concentration of DAS-β-CD shortened the total analysis time, we decreased the concentration step by step.…”

“…the resolution of enantiomers of MA was 13.2). Iwata et al 15 reported a method using sulfated(XIII)-γ-CD for the chiral analysis of 9 ATS by reversed-polarity CE/MS/MS. All 9 ATS were simultaneously separated with high chiral resolution (e.g.…”

Sensitive chiral analysis by capillary electrophoresis

“…The works included in this table are those in which the lowest LODs were obtained. MS detection has been employed in other works on chiral analysis by CE but LODs close to or above 10 25 M were generally obtained [125][126][127][128][129][130][131][132][133]. The basic instrumentation in CE-MS [134] allows, once the electrophoretic separation is performed, the introduction of the analytes in the mass spectrometer using an interface, usually a sheath liquid interface, which enables the establishment of the electrical contact and the nebulization of the solution.…”

18 Coupling CE and microchip-based devices with mass spectrometry

“…Other authors such as Otsuka et al 180 recommended to work with non-aqueous conditions to reduce the noise afforded by the presence of heptakis(2,3,6-tri-O-methyl)-b-cyclodextrin (TM-b-CD) as chiral selector in the BGE. The negatively charged highly sulfated g-CD (HSg-CD) was used by Iwata et al 181 for the simultaneous chiral separation of amphetamine-type stimulants. By using a relatively high concentration of HS-g-CD, amphetamines migrated as negatively charged complexes and were detected at the anode (reversed polarity mode).…”

“…Multitarget analysis and screening can be better performed with ion trap or TOF mass spectrometers. 181 On the other hand, the use of MS/MS can greatly enhance selectivity using the selected reaction-monitoring (SRM) mode that ensures more accurate measurements and lower limits of quantitation (LOQ) by reducing the chemical noise.…”