Determination of theophylline binding to human serum proteins by isotachophoresis.
Free theophylline was isolated from human serum by ultrafiltration and analysed in a leading electrolyte of 7.5 mM morpholinoethanesulphonic acid with ammediol as a counter ion at pH 8.90 and alpha-alanine as a terminator. The UV (280 nm) absorbance of the theophylline spike between serine and bicine as spacers was integrated. Binding percentages to human pool serum, human albumin and alpha 1-acid glycoprotein (orosomucoid) were determined at physiological concentrations, and found to be 55, 44 and 12%, respectively. The calibration lines were straight from 0 to 30 mg/l, with a standard deviation of 0.2 mg/l. The detection limit was 1 mg/l. The time of analysis was 12 min at 40 microA in a 0.2 mm I.D. capillary.
D001798:Blood Proteins / Q000378:metabolism; D004586:Electrophoresis / Q000379:methods; D006801:Humans; D009961:Orosomucoid / Q000378:metabolism; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013806:Theophylline / Q000097:blood*
D001798:Blood Proteins; D009961:Orosomucoid; D012709:Serum Albumin; D013806:Theophylline