The CORESTA Sub-Group TSNA in Air-Cured and Fire-Cured Tobacco carried out a study to obtain a better understanding of the best way to prepare samples for TSNA analysis in order to obtain reliable data. This study tested the effect on TSNAs of different drying regimes using high and low converter selections of TN 90.

The study showed that the recommendation would be to dry samples for TSNA analysis with any of the following methods: (1) air-drying, (2) freeze-drying, (3) oven-drying at temperatures no higher than 30 °C, in an oven with good airflow.