Gas chromatographic-mass spectrometric quantification of 4-(5-)-methylimidazole in roasted coffee after ion-pair extraction

• Type: Article in International Scientific Journal
• Date: 2002

Authors

Casal, S (Author) FFUP; Fernandes, JO (Author) FFUP; Oliveira, MBPP (Author) FFUP; Ferreira, MA (Author) Other

Journal

Title: Journal of Chromatography A

Vol. 976

Pages: 285-291

ISSN: 0021-9673

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 49 Citations

Scopus - 54 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-000-ME3

DOI: 10.1016/s0021-9673(02)01154-8

Abstract (EN): A GC-MS method is described for quantification of 4-(5-)methylimidazole (4MI) in coffee. Although tested, GC-flarne ionization detection proved inadequate for this purpose due to the complexity of the coffee matrix. The developed method was based on ion-pair extraction with bis-2-ethylhexylphosphate and derivatization with isobutylchloroformate. Quantification was carried out by the standard addition method using 2-ethylimidazole as internal standard. Reproducibility data from the complete procedure are presented. Mean recoveries were higher than 98%. The method was applied to green and roasted coffee samples from the two most important varieties, arabica and robusta, and to commercial "torrefacto" coffee blends. 4MI was not detected in the green coffee samples analysed and ranged from 0.307 to 1.241 mg/kg in roasted samples.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7