Determination of Trace Metal Ions in Human Hair byCapillaryElectrophoresis

A method was developed for the determination of trace metal ions in human hair by capillary electrophoresis.The effect factors such as the buffer type, detection wavelength, buffer concentration, buffer pH, separation voltage and column temperature were investigated.Five metal ions of Ca²⁺, Mg²⁺, Fe²⁺, Zn²⁺, Cu²⁺ were separated and determination within 7 min utilizing the concentration of 20 mmol/L imidazole (pH adjusted to 4.0 by acetic acid) as the background electrolyte solution and the pressure injection (50 mba×5 s),the separation voltage of 15 kV,the detection wavelength was set at 214 nm and the column temperature was 25℃.The linear range ranged from 0.25 to 100.00 mg/L, the detection limit ranged from 0.10 to 1.00 mg/L.Determination of repeat 5 times, the relative standard deviation (RSD) of retention time was less than 0.5%, the relative standard deviation (RSD) of peak area was less than 2.6%.The results of spiked recovery were good and the recoveries were obtained from 94.3% to 104.0%.The method was simple, fast, reproducible and high accuracy.The determination resultsofmetal ionswere accurate and had no significant difference compared with inductively coupled plasma atomic emission spectrometry (ICP-AES) when applied to the human hair sample analysis.