Simultaneous determination of 2-(hydroxymethyl)-N-nitrosothiazolidine-4-carboxylic acid and 2-(hydroxymethyl)-N-nitrosothiazolidine in smoked meats and cheese

A method is described for the determination of the two title compounds in various cured smoked meats, including bacon, smoked poultry products, and smoked cheeses. It is based on (a) extraction of the sample with methanol or acetonitrile, (b) removal of fats and lipids by partitioning of the extract with isooctane, (c) cleanup and separation of the two compounds on an acidic alumina sample preparation cartridge, (d) derivatization of 2-(hydroxymethyl)-N-nitrosothiazolidine-4-carboxylic acid to its methyl ester (HMNTCA-ME), and (e) determination of HMNTCA-ME and 2-(hydroxymethyl)-N-nitrosothiazolidine (HMNTZ) by high-performance liquid chromatography thermal energy analyzer technique. The recoveries of HMNTHZ and HMNTCA added to various products at 10-20 and 50-200 ppb, respectively, varied between 82-112% (mean, 94%) and 58-101% (mean, 79%). Confirmation was carried out by gas-liquid chromatographic-mass spectrometric analysis of HMNTHZ as its 0-methyl ether and of HMNTCA-ME as its heptafluorobutyryl derivative