Abstract: A process is provided for analyzing and detecting in an aqueous based mobile phase sample one or more N-nitroso compounds, which process includes the steps of injecting the aqueous based sample into a high pressure chromatograph to produce a liquid effluent where the nitroso compounds are resolved and separated, mixing the liquid effluent with an inert gas to produce a biphasic gas/liquid mixture, irradiating the biphasic mixture under ultraviolet irradiation to convert the nitroso compounds to nitric oxide gas, and detecting the nitric oxide produced.

Abstract: The invention relates to a photolytic interface and its use in series between a High Pressure Liquid Chromatograph (HPLC) and a chemiluminescence detector for the detection of trace (nanogram) amounts of N-nitroso compounds including N-nitrosamides and non-volatile N-nitrosamines in aqueous-based fluid samples. HPLC effluent containing separated N-nitrosoamino acids and N-nitrosoamino amides is introduced into a glass coil with a purge stream of He and irradiated with ultraviolet light. Nitric oxide cleaved by photolysis is rapidly separated from solvent through a series of cold traps and carried by the He into the reaction chamber of a chemiluminescence detector. Biological matrices, such as urine and gastric fluid, can be analyzed directly at high sensitivity without concentration and/or extraction.