Development of a rapid screening procedure for the detection of nitrite, nitrate, and total N-nitrosamine in environmental and physiological samples.

摘要

A rapid method for the detection of total N-nitrosamine and nitrite content of environmental and physiological samples has been achieved. Microliter volumes of nitrosamines are injected into a reaction vessel containing hot acid iodide treated ethylene glycol. As a result, the nitroso bond is broken resulting in the formation of the secondary parent amine and nitric oxide. Nitric oxide formed in this fashion is then swept by carrier gas into a chemiluminescence detector thereby generating a signal. Hence, the concentration of total nitrosamine and nitrite are determined. A second injection of the same sample is made into another reaction vessel containing warm hydrochloric acid. In this reaction vessel, nitrite is reduced while nitrate and nitrosamine are not. The difference in the two integrated signals yields the nitrosamine concentration for the sample.;The EGB method has a limit of detection of 1.0 nanogram as N-dimethylnitrosamine-N and 0.30 nanograms as nitrite-N. The method has been used to analyze beverages, tobacco products and human urine. Percent recoveries are quantitative and reproducibility is within 5% for standards and 20% for physiological samples.