A novel method for Co(II) and Cu(II) analysis by capillary electrophoresis with chemiluminescence detection

Based on the fact that some metal ions can catalyze the chemiluminescence (CL) reaction of luminol with K3Fe(CN)6, a novel capillary electrophoresis CL method was developed for the determination of Co(II) and Cu(II). The separation was carried out with a 10 mmol/L sodium acetate solution containing 0.8 mmol/L luminol and 2.0 mmol/L α-HIBA (adjusted to pH 4.8 by HAc solution). The post-capillary reagent was 2.0 mmol/L K3Fe(CN)6 which was adjusted to pH 13.0 by NaOH solution. Under the optimum conditions, the detection limits (S/N = 3) for Co(II) and Cu(II) were 7.5 × 10−11 mol/L and 7.5 × 10−9 mol/L, with the linear range of 7.5 × 10−9 mol/L to 1.0 × 10−6 mol/L and 7.5 × 10−8 mol/L to 5.0 × 10−5 mol/L, respectively.