‘True’ and ‘Apparent’ Thiocyanate in Body Fluids of Smokers and Nonsmokers

Abstract

True thiocyanate and total chromogens were measured in the body fluids of 8 smokers and 6 nonsmokers. It was found that smokers had much higher true SCN-levels (3-6 fold) than did nonsmokers in plasma, saliva and urine. The higher levels of total chromogens in smokers reported by earlier workers are due entirely to higher true SCN- content. Thermal sweat followed the same pattern (one smoker and nonsmoker studied). For both groups, saliva had the highest ratio of true to apparent SCN- and urine the lowest ratio. The higher true SCN-of smokers is probably directly associated with smoking, since cessation of smoking was accompanied by a gradual but marked decrease in true SCN- of all body fluids. Results do not invalidate the continued use of the nonspecific ferric nitrate method of analyzing plasma when measuring SCN-space.