Zinc determination in pleural fluid

In this study, an enzymatic zinc determination method was applied to pleura l fluid, the basis of which was the regaining of the activity of apo carbon ic anhydrase by the zinc present in the sample. The method was used for ple ural fluid zinc determination in order to show the application to body flui ds other than serum. For this purpose, pleural fluids were obtained from 20 patients and zinc concentrations were determined. Carbonic anhydrase was purified by affinity chromatography from bovine eryt hrocytes. The zinc present in its structure was removed by dialysis against dipicolinic acid, resulting in apoenzyme obtained at a ratio of 100%. The activity of the enzyme was determined by the esterase action on p-nitrophen yl acetate. For comparison, the same samples were analyzed in atomic absorp tion. The results obtained were evaluated statistically. (>0.05 t-test, <0. 001 Zn2+ (AA)-Zn2+ (apoCA), <0.005 Zn2+ (apocA)-Total protein).