Evaluation of colorimetric method for zinc, using clinical chemistry analyzer

We developed a colorimetric reagent kit for determination of zinc in serum, “ACCURAS AUTO Zn”. The reagent is applicable to all auto-analyzers widely used in hospital laboratories, without any serum pretreatment. Within-run and between-run precisions(C. V. )were 0.7-1.0% and 1.4-1.9%, respectively. The calibration curve was linear up to 500 µg/dl, and the detection limit was 5 µg/dl. Interference from iron and copper was eliminated by a masking agent. A good correlation(r = 0.996)was obtained between the results of the present method and those of atomic absorption spectrophotometry. This kit enables accurate and immediate assay of zinc with a clinical chemistry auto-analyzer, and saves time and efforts in the field of a nutrition support team(NST)work in hospitals.