A Comparison of Some Derivatives of Primary Amines for Gas Chromatography Using Electron Capture Detection

Abstract

Thirteen derivatives of phenethylamine were prepared. The sensitivities of flame ionization and electron capture detectors to these compounds and the original amine were determined. All compounds showed approximately the same sensitivity of detection with a flame ionization detector, but with an electron capture detector there was a 2 × 10⁵ difference in sensitivity of detection between the derivatives showing the greatest and the least sensitivity. The derivative with the greatest sensitivity of detection was the pentafluorobenzaldehyde-amine condensation product and amounts of the amine down to 10 picograms could easily be quantified.     

The GLC Separation of Amphetamine and Ephedrines as Pentafluorobenzamide Derivatives and Their Determination by Electron Capture Detection

Abstract

β-Phenylethylamine was converted to its trifluoroacetamide (TFA), pentafluoropropionamide (PFP), heptafluorobutyramide (HFB), pentadecafluorooctanamide (PDFO) and pentafluorobenzamide (PFBO) derivatives. The gas chromatographic characteristics and flame ionization versus electron capture detection properties were investigated. The PFBO derivative showed excellent detection enhancement, and consequently it was chosen for further study with the drugs amphetamine and various ephedrines. Linear electron capture detector responses were shown by these N-acyl derivatives in the sub-nanogram region and the limits of detection, depending upon the specific compound, were between 10 and 60 pg. It is proposed that the PFBO derivative, subsequent to the development of an isolation procedure, will prove admirably suitable to the determination of these and similar drugs in plasma after administration of therapeutic dosages.     

New Derivatives of (3,4-Dihydroxyphenyl)ethyleneglycol (DHPG) Suitable for Mass Fragmentography (MF)

Abstract

(3,4-dihydroxyphenyl)ethyleneglycol (DHPG) is condensed with methaneboronic or n-butaneboronic acids with or without previous acetylation of the phenolic groups. The derivatives so obtained are suitable for selective ion monitoring during gas chromatographic/ mass spectrometric analysis of DHPG alone or together with (3-methoxy-4-hydroxyphenyl)ethyleneglycol (MHPG).     

The Glc Separation of Indole Amines and Indole Alcohols as Heptafluorobutyryl Derivatives

Abstract

Indole amines and indole alcohols were converted to heptafluoro-butyryl (HFB) derivatives by an acyl transfer reaction with heptafluoro-butyrylimidazole. The indole NH group as well as all amino and hydroxyl groups were acylated. The HFB derivatives have excellent gas chroma-tographic properties and can be used with either hydrogen flame or electron capture detection systems. Mass spectra of the HFB derivatives of biologic N, N-dialkyl indole amines are very characteristic; these compounds can be identified easily by GLC-MS methods.     

A Study on Effective Derivatization for Ultra-Micro Detection of Dopamine by Gas Chromatography / Electron Capture Negative Ion Chemical Ionization Mass Spectrometry

Abstract

N-Pentafluorobenzenesulfonyl-O-bis (trimethylsilyl) dopamine was prepared and its properties were discussed for ultra-micro detection of dopamine by gas chromatography / electron capture negative ion chemical ionization mass spectrometry (GC/ECNICIMS). Detection of this derivative was at least 100 times as sensitive by GC/ECNICIMS as by gas chromatography / positive ion chemical ionization mass spectrometry. Deuterium labelled dopamine, dopamine analog phenethylamine and deuterium labelled phenethylamine were also derivatized, respectively, to reveal the fragmentation mechanism of the dopamine derivative. the high sensitivity and speculated fragment ion composition of the derivative by GC/ECNICIMS showed a possibility for highly sensitive detect ion of dopamine.     

The role of sample preparation in multidimensional gas chromatographic separations for non‐targeted analysis with the focus on recent biomedical,food, and plant applications

In this review, we consider and discuss the affinity and complementarity between a generic sample preparation technique and the comprehensive two‐dimensional gas chromatography process. From the initial technical development focus (e.g., on the GC×GC and solid‐phase microextraction techniques), the trend is inevitably shifting toward more applied challenges, and therefore, the preparation of the sample should be carefully considered in any GC×GC separation for an overreaching research. We highlight recent biomedical, food, and plant applications (2016–July 2020), and specifically those in which the combination of tailored sample preparation methods and GC×GC–MS has proven to be beneficial in the challenging aspects of non‐targeted analysis. Specifically on the sample preparation, we report on gas‐phase, solid‐phase, and liquid‐phase extractions, and derivatization procedures that have been used to extract and prepare volatile and semi‐volatile metabolites for the successive GC×GC analysis. Moreover, we also present a milestone section reporting the early works that pioneered the combination of sample preparation techniques with GC×GC for non‐targeted analysis.