Identification and quantitative determination of nitrosoproline and nitrososarcosine and preliminary investigations on nitrosohydroxyproline in cured meat products.

A method for the quantitative determination of certain nonvolatile N-nitrosoamino acids has been developed. After a clean up procedure, using liquid-liquid extraction and ion exchange separation, the nitrosoamino acids are determined either by GC after conversion to their methylesters or by photolysis and subsequent determination of formed nitrite ion. Identification is made by GC-MS. Nitrosoproline and nitrososarcosine can be determined unambiguously; work on nitrosohydroxy-proline is in progress. Analysis of some cured meat products has shown that nitrosoproline may be present in relatively large amounts (340-440 mug/kg, confirmed by GC-MS) as compared to the amounts of volatile in notrosamines commonly found in these products. A trace of nitrososarcosine (about 10 mug/kg) was found in one product.