TY - JOUR

T1 - Liquid-phase microextraction and capillary electrophoresis of citalopram, an antidepressant drug

AU - Halvorsen, Trine Grønhaug

AU - Pedersen-Bjergaard, Stig

AU - Rasmussen, Knut E.

PY - 2001/2/9

Y1 - 2001/2/9

N2 - A newly developed disposable device for liquid-phase microextraction (LPME) was evaluated for the capillary electrophoresis (CE) of the antidepressant drug citalopram (CIT) and its main metabolite N-desmethylcitalopram (DCIT) in human plasma. CIT and DCIT were extracted from 1 ml plasma samples through hexyl ether immobilised in the pores of a porous polypropylene hollow fibre and into 25 μl of 20 mM phosphate buffer (pH 2.75) present inside the hollow fibre (acceptor phase). Prior to extraction, the samples were made strongly alkaline in order to promote LPME of the basic drugs. Owing to the high ratio between the volumes of sample and acceptor phase, and owing to high partition coefficients, CIT and DCIT were enriched by a factor of 25 to 30. In addition, sample clean-up occurred during LPME since salts, proteins and the majority of endogenic substances were unable to penetrate the hexyl ether layer. Since the extracts were aqueous, they were injected directly into the CE instrument. Limits of quantification (S/N = 10) for CIT and DCIT in plasma were 16.5 ng/ml and 18 ng/ml respectively, while the limits of detection (S/N = 3) were 5 ng/ml and 5.5 ng/ml respectively. This enabled CIT (and DCIT) to be analysed within the therapeutic range by LPME-CE and detection limits were comparable with previously reported HPLC methods.

AB - A newly developed disposable device for liquid-phase microextraction (LPME) was evaluated for the capillary electrophoresis (CE) of the antidepressant drug citalopram (CIT) and its main metabolite N-desmethylcitalopram (DCIT) in human plasma. CIT and DCIT were extracted from 1 ml plasma samples through hexyl ether immobilised in the pores of a porous polypropylene hollow fibre and into 25 μl of 20 mM phosphate buffer (pH 2.75) present inside the hollow fibre (acceptor phase). Prior to extraction, the samples were made strongly alkaline in order to promote LPME of the basic drugs. Owing to the high ratio between the volumes of sample and acceptor phase, and owing to high partition coefficients, CIT and DCIT were enriched by a factor of 25 to 30. In addition, sample clean-up occurred during LPME since salts, proteins and the majority of endogenic substances were unable to penetrate the hexyl ether layer. Since the extracts were aqueous, they were injected directly into the CE instrument. Limits of quantification (S/N = 10) for CIT and DCIT in plasma were 16.5 ng/ml and 18 ng/ml respectively, while the limits of detection (S/N = 3) were 5 ng/ml and 5.5 ng/ml respectively. This enabled CIT (and DCIT) to be analysed within the therapeutic range by LPME-CE and detection limits were comparable with previously reported HPLC methods.

KW - Citalopram

KW - Liquid-phase microextraction

KW - N-Desmethylcitalopram

UR - http://www.scopus.com/inward/record.url?scp=0035830635&partnerID=8YFLogxK

U2 - 10.1016/S0021-9673(00)00868-2

DO - 10.1016/S0021-9673(00)00868-2

M3 - Journal article

C2 - 11218145

AN - SCOPUS:0035830635

VL - 909

SP - 87

EP - 93

JO - Journal of Chromatography

JF - Journal of Chromatography

SN - 0301-4770

IS - 1

ER -