The polarographic determination of zinc and manganese in plant and animal tissues and soils

A method is proposed whereby microgram quantities of zinc and manganese may be simultaneouly extracted with excess sodium diethyldithiocarbamate in the presence of tartrate at pH 5.5, the extracts decomposed and the metals polarographed in a lithium chloride supporting electrolyte. Iron must first be removed with cupferron, and the interference by cobalt and nickel is overcome by the use of dimethylglyoxime prior to the extraction. The method may be applied to the digests of animal tissues, plant materials or soils.