Analysis of N-nitrosodimethylamine in smokeless tobacco by use of UHPLC-MS/MS
N-nitrosodimethylamine (NDMA) is a member of the compound group N-nitrosamines and is a carcinogenic substance belonging to IARC Group 2A. In addition, NDMA is on the FDA "Established List for Harmful and Potentially Harmful Constituents in Tobacco Products and Tobacco Smoke". Therefore a sensitive and reliable NDMA analysis method is important for many tobacco industry laboratories.
In this presentation, an UHPLC-MS/MS (Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry) NDMA analysis method which has been operating reliably since 2008 will be presented.
NDMA is extracted for 40 min from the smokeless tobacco sample with ethyl acetate after the addition of deuterium-labelled internal standard (NDMA-d6). The extraction is followed by centrifugation and finally transfer of the particle-free ethyl acetate extracts to vials for UHPLC-MS/MS analysis. Although NDMA is injected in ethyl acetate (organic solvent) onto a reversed-phase column, the NDMA is well-retained on the column and elutes in a sharp, symmetric chromatographic peak. The working range of the method is 0.6-150 ng/g (standard sol. 0.1-50 ng/ml)
The method is accredited according to ISO17025 and the validation has been performed for snus, moist snuff and chewing tobacco with respect to specificity, precision, accuracy, limit of quantification and detection (LOQ and LOD), linearity, recovery, matrix effects and robustness.
To conclude; this is a sensitive and reliable method with a simple sample extraction procedure which has been analysing over 10000 sample extracts over the last seven years.