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.^[1] 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.

[1] Mehta S.K.; Rajesh B.J.; Dhalewadikar S.V. – CORESTA Congress, Edinburgh, 2010, Smoke Science / Product Technology Groups, abstr. SSPT19