Proposed TSNA Sampling Protocol
Marlene Adams, Chair, R. J. Reynolds Tobacco company

·         For all samples regardless of type (stem, lamina, green, or cured) the most critical features to insure accurate data are:

                  o       Moisture content

o       Temperature (length of exposure time can interact to increase TSNA levels)

o       Sample size

      ·         Stems should always be separated from lamina prior to analysis.

·         For a representative sample, take a leaf from multiple plants at the 4 to 6 leaf position from the top.

·         For sampling cured leaf, ensure the sample is as dry as possible, < 18%; however, excess heat should be avoided.  (In processing this may be done prior to re-drying.)

                   o       Freeze-drying is the preferred method, but may not be available to all

o       If freeze-drying is not available, dry with low humidity not heat

o       Air dry in low humidity environments but ambient temperatures should not exceed 35 C

o       35 C should be the absolute maximum temperature, but should include forced air in humid areas or, if oven dried, as temperature approaches 35 C

o       Even samples with low moisture may have significant increases in TSNA if temperatures exceed 35 C

o       Do not over fill dryer, allow space for air flow

       ·         A ground sample is best, since it is more homogeneous and easily mixed, and it also cuts down on turn-around time for sample results.