Sweat sodium and chloride analysis using BM/Hitachi 911 ion-selective electrodes.

The suitability of Hitachi 911 ion-selective electrodes to analyse neat sweat samples for sodium and chloride was investigated. Sweat samples obtained using the Gibson and Cooke method were analysed by flame photometry for sodium and coulometry for chloride. Specimens obtained by the Wescor Macroduct collection procedure were analysed by ion-specific electrodes. No significant differences between sodium and chloride results were found between the two different collection methods and analysis procedures. Analysis of neat sweat can reduce errors in sweat analysis by eliminating extraction and dilution stages. Errors could occur with use of a serum compensator in the calibration of ion-selective electrodes.