Determination of free calcium and calcium-containing species in human plasma by capillary electrophoresis-inductively coupled plasma optical emission spectrometry.
A new method for the determination of free calcium concentration in human plasma was developed by online coupling capillary electrophoresis (CE) with inductively coupled plasma optical emission spectrometry (ICP-OES). Baseline separation of calcium-containing species was achieved by CE-ICP-OES in a 120-cm-long capillary with 100-microm internal diameter, at 20 kV applied voltage, with a 30 mmol/L Tris-HCl buffer at pH 7.4. A total of eight calcium-containing species were found in human plasma; the concentration of free calcium ion was found to be 41.9 mg/L. The concentrations of calcium for other seven calcium species, estimated from the calibration against Ca(2+) standard, were 3.14-15.6 mg/L. The precision (RSD, n = 10) ranged from 1.2 to 2.7% for the migration time and 2.8 to 3.9% for the peak area. The developed method was also applied to analyze plasma samples with recovery ranged from 94.5 to 102% for samples spiked with 40 mg/L free Ca(2+) ion.
College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin 541004, China. dengby16@163.com
Biyang
B
Deng
Pingchuan
P
Zhu
Yingzi
Y
Wang
Jinrong
J
Feng
Xianfeng
X
Li
Xiangshu
X
Xu
Hua
H
Lu
Qiumei
Q
Xu
D000418:Albumins; D002118:Calcium / Q000097:blood*; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D004867:Equipment Design; D005916:Globulins; D006801:Humans; D011485:Protein Binding; D013057:Spectrum Analysis
D000418:Albumins; D005916:Globulins; D002118:Calcium