URI | http://purl.tuc.gr/dl/dias/DD1489D4-B80C-4C08-AD9A-C385673329B7 | - |
Αναγνωριστικό | https://doi.org/10.1016/j.aca.2012.01.019 | - |
Γλώσσα | en | - |
Μέγεθος | 6 pages | en |
Τίτλος | Vacuum-assisted headspace solid phase microextraction: Improved extraction of semivolatiles by non-equilibrium headspace sampling under reduced pressure conditions | en |
Δημιουργός | Elefteria Psillakis | en |
Δημιουργός | Evangelia Yiantzi | en |
Δημιουργός | Lucia Sanchez-Prado | en |
Δημιουργός | Nicolas Kalogerakis | en |
Εκδότης | Elsevier | en |
Περίληψη | A new headspace solid-phase microextraction (HSSPME) procedure carried out under vacuum conditions
is proposed here where sample volumes commonly used in HSSPME (9 mL) were introduced into
pre-evacuated commercially available large sampling chambers (1000 mL) prior to HSSPME sampling.
The proposed procedure ensured reproducible conditions for HSSPME and excluded the possibility of
analyte losses. A theoretical model was formulated demonstrating for the first time the pressure dependence
of HSSPME sampling procedure under non equilibrium conditions. Although reduced pressure
conditions during HSSPME sampling are not expected to increase the amount of analytes extracted at
equilibrium, they greatly increase extraction rates compared to HSSPME under atmospheric pressure
due to the enhancement of evaporation rates in the presence of an air-evacuated headspace. The effect is
larger for semivolatiles whose evaporation rates are controlled by mass transfer resistance in the thin gas
film adjacent to the sample/headspace interface. Parameters that affect HSSPME extraction were investigated
under both vacuum and atmospheric conditions and the experimental data obtained were used to
discuss and verify the theory. The use of an excessively large headspace volume was also considered. The
applicability of Vac-HSSPME was assessed using chlorophenols as model compounds yielding linearities
better than 0.9915 and detection limits in the low-ppt level | en |
Τύπος | Peer-Reviewed Journal Publication | en |
Τύπος | Δημοσίευση σε Περιοδικό με Κριτές | el |
Άδεια Χρήσης | http://creativecommons.org/licenses/by/4.0/ | en |
Ημερομηνία | 2015-09-25 | - |
Ημερομηνία Δημοσίευσης | 2012 | - |
Βιβλιογραφική Αναφορά | E. Psillakis, E. Yiantzi, L. S.Prado, N. Kalogerakis, "Vacuum-assisted headspace solid phase microextraction: Improved extraction of
semivolatiles by non-equilibrium headspace sampling under reduced pressure
conditions ",Anal.a chim. acta, vol.742 , pp. 30-36, 2012.doi:10.1016/j.aca.2012.01.019 | en |