title: On-line combination of high-performance liquid chromatography and total N-nitroso determination apparatus for the determination of N-nitrosamides and other N-nitroso compounds, and some recent data on the levels of N-nitrosoproline in foods and beverages.
abstract: A simple high-performance liquid chromatographic chemiluminescence detection method has been developed for the quantitative determination of N-nitrosamides and is based on post-column denitrosation of the compounds with hydrogen bromide-acetic acid or hydrogen iodide-acetic acid, followed by detection of the liberated NO by a chemiluminescence detector (TEATM). The method was used for the simultaneous analysis of DiazaldR, N-nitroso-N-methylurea, N-methyl-N'-nitro-N-nitrosoguandine and streptozotocin standards, and for N-methyl-N-nitrosourea extracted from model-system reaction mixtures and spiked, cured meats. The minimum detection limit of N-methyl-N-nitrosourea was about 0.5 ng. The method for the determination of N-nitrosarcosine and N-nitrosoproline in foods and beverages has been improved by replacing diazomethane with a mixture of BF3-methanol as the esterifying reagent and by simplifying the clean-up technique for purifying the prepared methyl esters. The average levels of N-nitrosoproline detected in 11 malts, 37 beers, 11 samples of fried bacon and 18 cured-meat products were found to be 24.1 micrograms/kg (5-113), 1.7 micrograms/kg (undetectable-6.0), 19.0 micrograms/kg (0.9-67.5), and 3.2 micrograms/kg (undetectable-21.6), respectively.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D001628:Beverages / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods; D004055:Differential Thermal Analysis; D005504:Food Analysis; D009602:Nitrosamines / Q000032:analysis; D009603:Nitroso Compounds / Q000032:analysis*
chemical_list: D000596:Amino Acids; D009602:Nitrosamines; D009603:Nitroso Compounds; C013621:nitrosamides; C010259:nitrosoproline