Anion-exchange chromatography to determine the concentration of chloride in sweat for diagnosis of cystic fibrosis.

For the diagnosis of cystic fibrosis, we use the "Macroduct Sweat Collection System" (Wescor) to sample sweat, and anion-exchange chromatography to determine its chloride content. The chromatographic system consists of a Whatman Partisil SAX 10-microns column, an isocratic phosphate-buffered mobile phase, and ultraviolet detection at 200 nm. The sweat chloride concentrations of 10 individuals with cystic fibrosis ranged from 101 to 131 mmol/L (mean 111, SD 9 mmol/L). For 11 controls the values ranged from 13 to 54 mmol/L (mean 28, SD 11 mmol/L). We conclude that the procedure is reliable for the diagnosis of cystic fibrosis.