A simple, highly sensitive colorimetric method for the determination of zinc in serum.

A simple, reliable, highly sensitive method for the determination of zinc in biological fluids is described. Interfering trace metals are removed as insoluble iodides or hydroxides prior to complex formation of zinc with dithizone in a Tris-buffered trichloroacetate centrifugate. Absorbance of the chelate is read at 555 nm. The sensitivity of the new method is comparable to that of atomic absorption spectrophotometry, and the results of zinc determinations of 23 sera by the two procedures agree to within acceptable limits of experimental error.