Determination of free fatty acids in chocolate by liquid chromatography with tandem mass spectrometry.
This paper describes a rapid extraction method, based on a matrix solid-phase dispersion technique using diatomaceous earth as solid support and 50:50 (v/v) chloroform/methanol as extracting solvent, that can determine 11 free fatty acids in chocolate. The extraction procedure is followed by reversed-phase liquid chromatography/tandem mass spectrometry (LC/MS/MS) using a normal-bore (4.6 mm i.d.) C-18 column and an electrospray interface operating in the negative ion mode. The tandem mass spectra of selected compounds show that charge-remote fragmentation (CRF) mechanisms are occurring; the intensities of the CRF reactions increase with the carbon number and degree of unsaturation of the fatty acids. Average recoveries, evaluated by the standard addition method, vary between 79-103%, and the estimated quantification limits are less than 153 ng/g. The proposed method has been used to analyse nine chocolate samples from various price ranges, bought from supermarkets.
Perret
Daniela
D
Laboratorio Chimico per la Sicurezza, Dipartimento di Chimica, Università La Sapienza, Piazzale Aldo Moro 5, P.O. Box 34, Posta 62, 00185 Rome, Italy.
Gentili
Alessandra
A
Marchese
Stefano
S
Sergi
Manuel
M
Caporossi
Lidia
L
D002099:Cacao / Q000737:chemistry*; D002182:Candy; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005230:Fatty Acids, Nonesterified / Q000032:analysis* / Q000145:classification; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D005230:Fatty Acids, Nonesterified