Nitrite, nitrate and N-nitroso cpds. detection in samples - by chromatographing, pyrolyzing and measuring amt. of nitric oxide produced

摘要

Method for measuring the amount of nitrate and nitrile cpds. and opt. N-nitroso cpds. in a sample comprises (A) chromatographically sepg. the nitrite and, nitrate and N-nitroso cpds. from each other and from other cpds. by passing the sample through a liquid chromatograph column wherein the sample is dissolved in a solvent, (B) continuously pyrolysing the dissolved sample from the column to selectively liberate NO in the gaseous phase from the nitrite and nitrate, and N-nitroso cpds, the pyrolysation converting the solvent and other parts of the sample into the gaseous phase, (C) continuously passing the pyrolyser product through a cold trap to condense solvent and other parts of the sample and leave the NO in the gaseous phase and (D) continuously measuring the amount of NO contained in the cold trap effluent. N-nitroso cpds which are among the most carcinogenic cpds. known are found in artificial food additives and tobacco smoke, but tolerable levels are not known as reliable methods for their determination are not known. The present method provides such a reliable method.