Gulf Coast Conference 2022

Capillary Option for ASTM D3606

ASTM method D3606 is used to separate benzene and toluene in spark ignition fuels. Analysts may use capillary (option A) or packed (option B ) columns for this method. The capillary option uses two columns connected in series, where the first column is the nonpolar dimethylpolysiloxane phase (Rxi-1ms, cat.# 13338) and the second is a polar “wax” phase (Stabilwax, cat.# 10657 ) column. After toluene is eluted from the first column, the first column is backflushed while an auxiliary EPC maintains flow through the second column. The complicated setup associated with the ASTM D3606 capillary option may make the method unappealing, but the results show the excellent separation of target analytes. We used Restek’s Rxi-1ms and Stabilwax to separate target analytes in D3606 standard 8.5.2 and a sample of gasoline and generated helpful tips for getting started and troubleshooting this method. Future work may consider the performance of this column set for a full method validation, and potential limitations.

Method Translator for PLOT Columns

Method translators are extremely helpful tools when modifying/developing a gas chromatographic (GC) method. Changes to GC method parameters such as inlet/outlet pressure; flow/carrier gas type; or even capillary column dimensions will result in different retention times for our analytes and will affect resolution. Method translators calculate new analysis conditions by keeping the analytes elution temperatures the same, thus preserving elution order. Using this tool, the analysis method can be translated to a different column dimension, carrier gas type, and linear velocity, for example, with very little time spent on the method development. Method translation works well for the columns with liquid stationary phases. The purpose of this work is to present the feasibility and accuracy of method translators for the porous layer open tubular (PLOT) columns.