Determination of Free Calcium in Human Plasma by Capillary Electrophoresis-Inductively Coupled Plasma Atomic Emission Spectrometry
A new method was developed for the speciation analysis of calcium and determination of free calcium concentration in human plasma by on-line capillary electrophoresis(CE) with inductively coupled plasma atomic emission spectrometry(ICP-AES).Baseline separation of calcium speciation was achieved by CE-ICP-AES under the conditions of separation voltage of 20 kV and running buffer of 30 mmol/L Tris-HCl(pH=7.4).The forms of calcium in plasma has eight species.One of them is free calcium.The relative standard deviation(RSD,n=10) was 1.3% to 1.8% for migration time.Free calcium concentration in plasma was 42.2 mg/L.The recovery spiked with 5 mg/L free calcium was 94.8% to 104%.The detection limit was 25 μg/L.