A simple and low-cost electrochemiluminescence detector for capillary electrophoresis.
A simple and cost-effective electrochemiluminescence (ECL) detector for capillary electrophoresis (CE) has been developed. The detector was constructed by vertically gluing a 0.5 mL plastic sample vial onto a piece of 1.5 cm x 1 cm x 0.6 mm indium/tin oxide (ITO)-coated glass plate. End-column ECL detection was performed in a wall-jet configuration. Potential control of the ITO electrode was provided using a direct current (DC) battery. Tris(2,2'-bipyridyl)ruthenium(III) (Ru(bpy)3(3+))-based ECL reaction was used for sensitive detection of four trialkylamines (trimethylamine, triethylamine, tripropylamine, tributylamine) and two amino acids (proline, hydroxyproline). With 15 mM sodium borate (pH 9.5) plus 3.5 mM Ru(bpy)3(2+) present in the detection cell and the ITO electrode biased at 1.7 V (vs. platinum wire reference), the test analytes can be efficiently separated and sensitively detected by the developed CE-ECL system. Linearity (r > or = 0.995) over two orders of magnitude and an average number of theoretical plates of 160 000/m were generally obtained. Reproducibility on peak height and migration times (n = 42) was 3.3% and 1.2% for tripropylamine, and 2.4% and 1.5% for proline, respectively. The detection limits were in the range of 2-5 microM (1-2 fmol) for the test analytes.
Chiang
Mei-Tsu
MT
Department of Chemistry, Tunghai University, Taichung, Taiwan.
Lu
Mei-Chun
MC
Whang
Chen-Wen
CW
D000588:Amines / Q000032:analysis; D003365:Costs and Cost Analysis; D004563:Electrochemistry / Q000295:instrumentation; D019075:Electrophoresis, Capillary / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D006909:Hydroxyproline / Q000032:analysis; D007204:Indium / Q000737:chemistry; D008163:Luminescent Measurements; D008839:Microelectrodes; D009942:Organometallic Compounds / Q000737:chemistry; D010984:Platinum / Q000737:chemistry; D011392:Proline / Q000032:analysis; D015203:Reproducibility of Results; D012428:Ruthenium / Q000737:chemistry; D013997:Time Factors
D000588:Amines; D009942:Organometallic Compounds; D007204:Indium; D010984:Platinum; C047711:indium oxide; D012428:Ruthenium; D011392:Proline; D006909:Hydroxyproline