In 2012, the CORESTA Smokeless Tobacco Sub-Group (now the Tobacco and Tobacco Product Analytes Sub-Group [TTPA]) conducted a collaborative study to evaluate the suitability of the CORESTA Recommended Methods (CRMs) Nos. 60 and 61 for the determination of two humectants, 1,2-propylene glycol (propylene glycol or PG) and glycerol (Gly), in smokeless tobacco products.

In 2015, the Routine Analytical Chemistry Sub-Group (RAC) proposed amending CRM 60 with the goal to increase the extraction efficiency of the GC method by adding water to samples prior to extraction with methanol. In 2016 a collaborative study was conducted to allow the repeatability and reproducibility to be calculated for the proposed revised method and compare the results to those obtained using CRM 61.

This report summarises the findings of the 2016 collaborative study, which shows that the repeatability (r) and reproducibility (R) data obtained for the proposed revised CRM 60 are comparable to that obtained previously for both the GC (CRM 60) and LC (CRM 61) methods undertaken in previous studies. CRM 60 was updated, but due to the low number of participants that used the LC technique for this study an update of CRM 61 was not planned.