Determination of copper and zinc in blood plasma by ion chromatography using a cobalt internal standard

Ion chromatography was used to detect levels of copper and zinc in blood plasma from renal dialysis patients on continuous ambulatory peritoneal dialysis (CAPD) and haemodialysis (HD). The developed method used cobalt as an internal standard and when combined with the standard additions method improved the overall precision of the results by between -0.3 and 6.0% and -0.8 and 5.7% for copper and zinc, respectively. The method was compared with inductively coupled plasma optical emission spectrometry (ICP-OES) and the results indicated no significant difference between the two methods with or without an internal standard. Without an internal standard, t(calc) was 0.869 with a t(crit) of 2.201 (n = 12, P = 0.05) and with an internal standard, t(caic) was 0.189 compared to a t(crit) of 2.201 (n = 12, P = 0.05). The copper and zinc levels in blood plasma in both dialysis groups were not significantly different to the copper and zinc levels in blood plasma of the control patients. A convenient method of analysis of trace elements in blood such as ion chromatography with UV/VIS detection is useful for determining whether inorganic elements may be disrupted in the body due to changes in the state of health.