Selection of Optimum Conditions for GC Operation

The optimum operating conditions for GC analysis must be determined prior to the GC-MS analysis. In general, this is accomplished by injecting the sample solution several times while varying such parameters as carrier gas, splitting ratio of carrier gas at the injection port fitted with a split liner, carrier gas flow rate, and oven temperature profile. In addition, the type of capillary column used and the concentration and volume of the sample to be injected also have to be optimized. 

The following GC operating conditions are optimal for phenolic compounds, including those present in spent pulping liquor or bleaching effluent with or without prior O-acetylation and subsequent O-methylation or O-ethylation  

Column DB-5 bonded phase, fused silica capillary column (30 m x 0.32 mm ID film thickness 0.25//m) or similar capillary column. 

Oven temperature profile hold 1 min at 60°C 60-140°C (15°C/min) 140-260°C (5°C/min) final temperature 260°C (lOmin) post value 270.007C (lOmin). 

Detector Flame Ionization Detector (FID) for non-halogenated compounds Electron Capture Detector (ECD) for halogenated compounds 

---