RT info:eu-repo/semantics/article
T1 Improved solid-phase extraction procedure for the isolation and in-sorbent pentafluorobenzyl alkylation of polyfunctional mercaptans
A1 Mateo Vivaracho, Laura María
A1 Cacho, Juan
A1 Ferreira, Vicente
K1 Thiols
K1 Pentafluorobenzylbromide
K1 GC–NCI-MS
K1 SPE
AB A fast method for the determination of aroma-powerful polyfunctional thiols at ng L−1 level has been developed. Mercaptans are selectively retained in a 50 mg solid-phase extraction cartridge and derivatization takes place in the same cartridge at room temperature (25 °C) in 20 min by adding small amounts of pentafluorobenzyl bromide (PFBBr) and a strong alkali: 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The corresponding derivatives are further eluted and determined by gas chromatography–negative ion mass spectrometry (GC–NCI-MS). Isolation, derivatization, clean-up, elution and calibration conditions were examined. Carrying the reaction in the cartridge makes it possible to use water and non-polar reagents simultaneously, to avoid large volumes of toxic solvent, and to eliminate the excess of reagent. This was last accomplished by the reaction with mercaptoglycerol and further rinsing with a hydromethanolic solution. The method makes it possible to simultaneously determine 2-methyl-3-furanthiol (MF), 2-furfurylthiol (2-furanmethanethiol) (FFT), 4-mercapto-4-methyl-2-pentanone (MP) (as its methoxime), 3-mercaptohexylacetate (MHA) and 3-mercaptohexanol (MH). Absolute limits of detection were 0.2 (MF), 0.1 (FFT), 0.1 (MP), 0.3 (MHA) and 2 (MH) ng L−1. Repeatability (1% < RSD < 20%) and linearity (0.978 < R2 < 0.999) were satisfactory. Problems with matrix effects were solved by the use of deuterated analogues for MP, MHA and MH and by avoiding the oxidation of analytes and standards via addition of cysteine and EDTA. The different aspects of the method optimization are discussed.
PB Elsevier
SN 0021-9673
YR 2008
FD 2008
LK https://uvadoc.uva.es/handle/10324/73737
UL https://uvadoc.uva.es/handle/10324/73737
LA eng
NO Journal of Chromatography A, 1185 (2008) 9–18
DS UVaDOC
RD 03-mar-2025