Optimized atomic absorption spectrophotometry of zinc in cerebrospinal fluid

This method for direct determination of Zn in cerebrospinal fluid (CSF) involves flame atomic absorption spectrophotometry with a pulse nebulizer technique. Standard solutions of Zn in 150 mmol/L NaCl were used. We could account for 88% of added standard with the method in individual samples from 10 patients and in pooled CSF. The method is acceptably precise, CVs in pooled CSF ranging from 4 to 12%. The mean CSF-Zn concentration for nine healthy men was 0.18 (SD 0.04) mumol/L and for nine healthy women 0.15 (SD 0.03) mumol/L, a statistically insignificant difference. These values are lower than those in previous reports, which may have been the result of contamination problems, nonatomic absorption, or nonstandardized sampling. In the healthy volunteers, the CSF-Zn concentration was positively correlated with serum-Zn, CSF-protein, and CSF-albumin concentrations, as well as with the CSF/serum ratio for albumin.