Microdiffusion method for estimation of cyanide in whole blood and its application to the study of conversion of cyanide to thiocyanate.

A microdiffusion technique has been used to separate and concentrate the nanomole amounts of cyanide in whole blood, and to permit its simplified colorimetric estimation (1). With this technique cyanide was measured in whole blood from normal smokers, normal nonsmokers, and patients suffering from tobacco amblyopia. Cyanide was also measured in whole blood from vitamin B12-deficient and normally fed Wistar rats. From the experimental animal results and results from patients, it is suggested that a more suitable index of cyanide exposure may be the alteration of plasma thiocyanate rather than the direct determination of whole blood cyanide.