Partial conversion of methanol to formaldehyde in the gas chromatography injection port and reactivity with amines
| Autor: | Laura A. Ciolino, Chian Sing Lai, Chee Leong Kee, Xiaowei Ge, Min Yong Low |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Phenylpropanolamine
Formaldehyde Alcohol Biochemistry Gas Chromatography-Mass Spectrometry Analytical Chemistry Isotopic labeling chemistry.chemical_compound Amines Oxazoles Ephedrine Chromatography Methanol Organic Chemistry Temperature Injection port General Medicine Solvent chemistry Solvents Amine gas treating Imines Gas chromatography Cyclobutanes |
| Zdroj: | Journal of Chromatography A. 1257:158-170 |
| ISSN: | 0021-9673 |
| DOI: | 10.1016/j.chroma.2012.08.021 |
| Popis: | The partial conversion of methanol (MeOH) to formaldehyde (HCHO) in the gas chromatograph (GC) injection port was studied. The presence of formaldehyde in the injection port can result in reaction with injected analytes, especially primary and secondary amines. A systematic study of this problem was undertaken using norephedrine and ephedrine as probe analytes, and experiments involving varying inlet temperature, comparisons among solvents and solvent mixtures, isotopic labeling, and formaldehyde spiking. These experiments showed a direct correlation between inlet temperature and formation of the amine-formaldehyde condensation products. The mass spectra of the norephedrine and ephedrine condensation products were consistent with addition of the methylene group derived from formaldehyde across the amine and alcohol moieties to form the corresponding oxazolidine-ring compounds. Results for the imine condensation product of didesmethylsibutramine formed in the injection port are also presented. |
| Databáze: | OpenAIRE |
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