SPME-GC/MS Analysis of Methanol in Biospecimen by Derivatization with Pyran Compound

Abstract

Methanol is metabolized in the body to highly toxic formaldehyde and formate when consumed accidentally. Methanol has been typically analyzed with gas chromatography-flame ionization detector (GC-FID). However, its retention time may overlap with other volatile compounds and lead to confusion. Alternative analysis of methanol using gas chromatography/mass spectrometry (GC/MS) also has limitations due to its similar molecular weight with oxygen and low boiling point. In this study, methanol and internal standard of deuterium-substituted ethanol were derivatized with 3,4-dihydro-2H-pyran under acid catalysis using concentrated hydrochloric acid. The reaction products including 2-methoxytetrahydropyran were extracted with solid-phase microextraction followed by GC/MS analysis. This method was successfully applied to measure the lethal concentration of methanol in the blood of a victim with a standard addition method to overcome the complex matrix effect of the biospecimen. Identification of the metabolite formate by ion chromatography confirmed the death cause to be methanol poisoning. This new method was a much more convenient and reliable process to measure methanol in complex matrix samples by reducing sample pretreatment effort and cost.

Application of Covalent Organic Porous Polymers-Functionalized Basalt Fibers for in-Tube Solid-Phase Microextraction

“…Some traditional methods, such as solid-phase extraction [ 7 , 8 ], stir bar sorptive extraction [ 9 ], liquid–liquid extraction [ 10 , 11 , 12 , 13 ], etc., have some disadvantages, like the consumption of a large volume of organic solvent, low extraction efficiency and poor sensitivity. Solid-phase microextraction (SPME) proposed by Pawlinszyn in 1989, not only overcomes the above shortcomings [ 14 , 15 , 16 ] but can also couple with gas chromatography (GC) [ 13 , 17 ], high-performance liquid chromatography (HPLC) [ 18 ] and other instruments. In particular, in-tube solid-phase microextraction (IT-SPME), which can be combined with HPLC [ 19 , 20 , 21 ], has been widely used in environmental, food, pharmaceutical and other analytical applications.…”