Guilty by dissociation: Part A: Development of a rapid Ultra-High Performance Liquid Chromatography (UHPLC)-MS/MS methodology for the analysis of regioisomeric diphenidine-derived Novel Psychoactive Substances (NPS)

A structural spectroscopic study of dissociative anaesthetic methoxphenidine

“…21,22 On the other hand, MXP can be detected using HPLC-MS methods either focused on the analyses of a large amount of samples in biological materials, 23 hair 24 or those focused on the separation of specific regioisomers of the MXP. 25–28…”

Guilty by dissociation: Part B: evaluation of Supercritical Fluid Chromatography (SFC-UV) for the analysis of regioisomeric diphenidine-derived Novel Psychoactive Substances (NPS)

“…Analytical differentiation of regioisomers is a significant challenge within forensic drug analysis but can be readily achieved using Nuclear Magnetic Resonance (NMR) spectroscopy [6], however, only a small number of laboratories have such instruments. The discrimination of specific regioisomers using this technique is both cost and labour intensive when compared to the gas chromatography-mass spectrometry (GC) [7], reversed-phase high performance liquid chromatography (RP-HPLC) [8,9] and ultra-high performance liquid chromatography-mass spectrometry-mass spectrometry (UHPLC-MS/MS) [10] approaches which have been applied to a number of regioisomeric 1, 2-diarylethylamines.…”

“…To date, SFC has been successfully employed in the pharmaceutical [17,18], environmental [19] and toxicology/forensic [20,21] sectors. This paper describes the first reported evaluation of SFC to separate 31 substituted derivatives of widely differing physical and chemical properties using a rapid generic gradient SFC methodology and compares it to their analysis by liquid chromatography [9,10]. The library included a range of derivatives possessing either electron donating/withdrawing substituents, commonly included in combinatorial libraries, of varying size and lipophilicity on the phenyl ring (see Fig.…”

“…1). The 2-, 3-and 4-positional isomers (commonly known as the ortho-, metaand para-regioisomers) of eight [7,10] to separate these isomeric compounds and to elucidate if their elution order was dependent on the position and type of substituent on the phenyl ring. The racemic diphenidines were analysed on a range of nine acidic, basic and neutral SFC stationary phases (Table 1) which have previously been demonstrated to exhibit differing chromatographic selectivity [22].…”

“…The racemic diphenidines were analysed on a range of nine acidic, basic and neutral SFC stationary phases (Table 1) which have previously been demonstrated to exhibit differing chromatographic selectivity [22]. The chromatographic selectivity using SFC conditions was compared to those previously reported using RP-UHPLC [10].…”