In December 2017, CORESTA Agro-Chemical Advisory Committee (ACAC) published the CORESTA Guide No. 21, which is preparatory to setting GRLs for cigar tobaccos to complement those for tobaccos used in cigarettes listed in the CORESTA Guide No. 1.

The Sub-Group Agrochemicals Analysis (SG AA) has conducted numerous rounds of proficiency testing or JETS (Joint Experiment Technical Study) since 2005, however dark air-cured (DAC) or dark fire-cured (DFC) tobacco was never used as test materials in these tests.

Matrix effects are a major concern in food analysis, because co-extractives in a sample extract are present. Moreover, these effects are observed as a decreased (suppression) or increased (enhancement) detector response, compared with that produced by a solvent solution of the analyte. This phenomenon can seriously affect the accuracy of an analytical method in tobacco samples.

This JETS describes a preliminary test to know if there are any differences in matrix effects (MEs) between DAC and two tobacco types: Burley (BLY) or Flue-cured Virginia (FCV).