N-nitrosamines (NA) are detected in rubber and vulcanizates by methanol extraction and subsequent detection employing GC-TEA. The use of ascorbic acid as an inhibitor oi nitrosation during extraction has a negative influence on the quality of the analysis. Interferences in the chromatogram hinder the classification and determination of N-nitroso dimethylamine (NDMA), N-nitroso diethylamine (NDEA) and N-nitroso dipropylamine (NDPA). This work elucidates the mechanism of the ascorbic acid disturbance. alpha-hydroxy acids decay at the temperature of the chromatographic columns by generating CO which will give a signal like NO at the TEA-detector. The use of hydroquinone instead of ascorbic acid avoids these interferences. in this way the determination of NDMA, NDEA and NDPA is significantly improved.