This study was performed to find an appropriate desorbing solution for 2MEA and 2EEA collected activated charcoal. The desorbing solution should be transesterification-free and have reliable desorption efficiency. Anumber of desorbing solutions were tested against CS2 and MeOH/ methylene chloride(5/95, v/v, 5MeOH) which were normally used as desorbing solutions. Transesterfication of 2MEA and 2EEA on dry charcoal by 5MeOH was also verified.
A GC/MSD was used for verification of transesterification. Desorption effciencies of several desorbing solutions were measured by GC/FID, As desorbing solutions, CS2, 5MeOH, DMF/CS2(1/99, v/v, 1DMF), and DMF/cs2(3/97,v/v, 3DMF)were selected.
Desorption effciencies of 2MEA and 2EEA were 97.3% and 99.2% by 5MeOH, respectively, and 100.8% and 101.4% by 3DMF, respectively. No significant difference between 5MeOH and 3DMF was found for both 2MEA and 2EEA(p〈0.05), Transesterification of 2MEA and 2EEA on dry charcoal at≥10 ppm was confirmed when 5MeOH was used as the desorbing solution, However, when 3DMF was used, no transestserification of 2MEA and 2MEEA on dry charcoal was found.
This study found that 3DMF (DMF/CS@, 3/97, v/v)was the desorbing solvent of choice for 2MEA and 2EEA collected on coconut shell charcoal tube With the solutiom, no transesterification was found with nearly 100% desorption efficiency.
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