Rapid Solid-Phase Extraction Method for the Detection of Volatile Nitrosamines in Food

A rapid solid phase extraction (SPE) method was developed to analyze volatile N-nitrosamines (NAm) in foods. The currently used vacuum distillation technique is time and solvent consuming and is cumbersome for multiple analyses. Our objective was to develop a robust analytical method to measure the eight most common volatile NAm found in foods. The extraction procedure was based on two consecutive extraction/concentration steps using Extrelut and Florisil SPE. The amounts of food sample and solvent required were reduced compared to the conventional vacuum distillation method without affecting the sensitivity which was at a 0.3 ppb detection limit. A greater confidence in the analyte detection was obtained by the use of a capillary GC column, instead of the conventionally used open packed column, prior to thermal energy analyzer (TEA) detection. Another advantage of our method is the use of commercial cartridges, which ensures reproducibility and standardization of the method for multiple analyses. An application of the SPE method to a survey of volatile NAm content in sausages and dried milk powder revealed no contamination (<0.3 ppb) of either of these food samples.