Determination of Sulpiride by Capillary Electrophoresis with End-Column Electrogenerated Chemiluminescence Detection

• Published in: Clinical chemistry (Baltimore, Md.) Md.), 2002-07, Vol.48 (7), p.1049-1058
• Main Authors: Liu, Jifeng, Cao, Weidong, Qiu, Haibo, Sun, Xiuhua, Yang, Xiurong, Wang, Erkang
• Format: Article
• Language: English
• Subjects: 2,2'-Dipyridyl - analogs & derivatives; 2,2'-Dipyridyl - chemistry; Acetates; Adult; Antidepressive Agents, Second-Generation - analysis; Antidepressive Agents, Second-Generation - blood; Antidepressive Agents, Second-Generation - urine; Antipsychotic Agents - analysis; Antipsychotic Agents - blood; Antipsychotic Agents - urine; Biological and medical sciences; Dopamine Antagonists - analysis; Dopamine Antagonists - blood; Dopamine Antagonists - urine; Electrochemistry; Electrophoresis, Capillary; Humans; Investigative techniques, diagnostic techniques (general aspects); Luminescent Measurements; Medical sciences; Methylene Chloride; Middle Aged; Miscellaneous. Technology; Organometallic Compounds - chemistry; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Receptors, Dopamine D2 - drug effects; Ruthenium; Solvents; Sulpiride - analysis; Sulpiride - blood; Sulpiride - urine
• ISSN: 0009-9147; 1530-8561
• DOI: 10.1093/clinchem/48.7.1049

Capillary electrophoresis (CE) with tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)3(2+)]-electrogenerated chemiluminescence (ECL) detection is a promising method for clinical analysis. In this study, a method combining CE with Ru(bpy)3(2+) ECL (CE-ECL) detection that can be applied to amine-containing clinical species was developed, and the performance of CE-ECL as a quantitative method for determination of sulpiride in human plasma or urine was evaluated. Sulpiride was separated by capillary zone electrophoresis in uncoated fused-silica capillaries [50 cm x 25 microm (i.d.)] filled with phosphate buffer (pH 8.0) and a driving voltage of +15 kV, with end-column Ru(bpy)3(2+) ECL detection. A platinum disc electrode was used as working electrode. Sulpiride in human plasma or urine samples (100 microL) was extracted by a double-step liquid-liquid extraction procedure, dried under nitrogen at 35 degrees C in a water bath, and reconstituted with 100 microL of filtered water. The extraction solvent was ethyl acetate-dichloromethane (5:1 by volume). Under optimum conditions (pH 8.0 phosphate buffer, injection for 6 s at 10 kV, and +1.2 V as detection potential), separation of sulpiride was accomplished within 4 min. The calibration curve was linear over a concentration range of 0.05-25.0 micromol/L, and the limit of detection was 2.9 x 10(-8) mol/L for sulpiride. Intra- and interday CVs for ECL intensities were