Aspects of Porous Graphitic Carbon as Packing Material in Capillary Liquid Chromatography

• In this thesis, porous graphitic carbon (PGC) has been used as packing material in packed capillary liquid chromatography. The unique chromatographic properties of PGC has been studied in some detail and applied to different analytical challenges using both electrospray ionization-mass spectrometry (ESI-MS) and ultra violet (UV) absorbance detection.The crucial importance of disengaging the conductive PGC chromatographic separation media from the high voltage mass spectrometric interface has been shown. In the absence of a grounded point between the column and ESI emitter, a current through the column was present, and changed retention behaviors for 3-O-methyl-DOPA and tyrosine were observed. An alteration of the chromatographic properties was also seen when PGC was chemically oxidized with permanganate, possibly due to an oxidation of the few surface groups present on the PGC material.The dynamic adsorption of the chiral selector lasalocid onto the PGC support resulted in a useful and stable chiral stationary phase. Extraordinary enantioselectivity was observed for 1-(1-naphthyl)ethylamine, and enantioseparation was also achieved for other amines, amino acids, acids and alcohols.Finally, a new strategy for separation of small biologically active compounds in plasma and brain tissue has been developed. With PGC as stationary phase it was possible to utilize a mobile phase of high content of organic modifier, without the addition of ion-pairing agents, and still selectively separate the analytes.

Ämnesord

NATURVETENSKAP  -- Kemi -- Analytisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Analytical Chemistry (hsv//eng)

Nyckelord

Analytical chemistry

PGC

porous graphitic carbon

stationary phase

packing material

LC

liquid chromatography

miniaturized

chiral

enantiomer

ESI

electrospray ionization

mass spectrometry

polar compounds

L-DOPA

dopamine

biological samples

biological matrix

Analytisk kemi

PGC

poröst grafitiserat kol

stationärfas

packningsmaterial

LC

vätskekromatografi

miniatyriserade system

kiral

enantiomer

ESI

electrospray jonisation

mass spektrometri

polära föreningar

L-DOPA

dopmamine

biologiska prover

biologisk matris

Analytical chemistry

Analytisk kemi

Analytical Chemistry

Analytisk kemi

Publikations- och innehållstyp

vet (ämneskategori)

dok (ämneskategori)