Open AccessSeparating chiral isomers of amphetamine and methamphetamine using chemical derivatization and differential mobility spectrometry
Author(s) -
Campbell J. Larry,
Kafle Amol,
Bowman Zack,
Blanc J. C. Yves Le,
Liu Chang,
Hopkins W. Scott
Publication year - 2020
Publication title -
analytical science advances
Language(s) - English
Resource type - Journals
ISSN - 2628-5452
DOI - 10.1002/ansa.202000066
Subject(s) - derivatization , chemistry , enantiomer , chromatography , analyte , mass spectrometry , capillary electrophoresis , diastereomer , acetonitrile , designer drug , analytical chemistry (journal) , organic chemistry , psychology , drug , psychiatry
The separation and analysis of chiral compounds, especially enantiomers, presents a great challenge to modern analytical chemistry, particularly to mass spectrometry (MS). As a result, integrated orthogonal separations, such as chiral liquid chromatography (chiral LC), gas chromatography (GC), or capillary electrophoresis (CE), are often employed to separate enantiomers prior to MS analysis. Here, we combine chemical derivatization with differential mobility spectrometry (DMS) and MS to separate and quantitate the transformed enantiomeric pairs R‐ and S‐amphetamine, as well as R‐ and S‐methamphetamine. We also demonstrate separation of these drugs by using reverse‐phase LC. However, while the LC method requires ∼5 min to provide separation, we have developed a flow‐injection analysis (FIA) method using DMS as the exclusive mode of separation (FIA‐DMS), requiring only ∼1.5 min with equivalent quantitative metrics (1‐1000 ng/mL range) to the LC method. The DMS‐based separation of each diastereomeric pair is driven by differences in binding energies between the analyte ions and the chemical modifier molecules (acetonitrile) added to the DMS environment.