Performance of a novel spectrophotometric lithium assay on a routine biochemistry analyser.

A new spectrophotometric lithium assay was assessed after adaption to a Hitachi 917. Results on this analyser were in close agreement with lithium measured on a flame photometer (95% confidence interval ± 0·06 mmol/L, n = 120). Assay precision was < 2·5% over a range of lithium concentrations from 0·5- 3·0 mmol/L. The assay was linear to 3 mmol/L and interference from haemolysis, icterus, lipaemia and other metal ions was minimal. The assay is a useful substitute or "back-up" for traditional lithium assays. Improved "on-board" calibration stability (currently 24 h) is required by improving the stability of uncapped reagent. [ABSTRACT FROM AUTHOR]