Safer nicotine analysis: proposed changes to CRM 35, total alkaloids in tobacco leaf
The most commonly used automated method for leaf nicotine analysis is CORESTA Recommended Method No. 35. This is based on the principle of continuous-flow analysis, using dialysis to remove interference from coloured leaf components followed by a colorimetric determination of alkaloids. The colour-producing reaction requires cyanogen chloride, CNCl, which is generated in situ from Chloramine T and KCN. As a result, considerable safety precautions are needed when preparing reagents and running the method.
In 2009 the Routine Analytical Chemistry Sub-Group considered a proposal for a safer nicotine method which generates the CNCl from NaOCl and KSCN. No special precautions are needed when handling the potassium thiocyanate. An inter-laboratory test was performed in 2010, with satisfactory results.
In 2010 Mehta et al. proposed an improved procedure that replaces NaOCl with dichloroisocyanurate ("DCIC"), which has the advantage of providing a more stable chlorine source than NaOCl. We have compared this method with CRM 35 and the NaOCl / KSCN procedure in one internal and two international inter-laboratory tests, and here present the results.
 Mehta S.K.; Rajesh B.J.; Dhalewadikar S.V. – CORESTA Congress, Edinburgh, 2010, Smoke Science / Product Technology Groups, abstr. SSPT19