THE OPTIMIZATION OF CAPACITY AND EFFICIENCY WHEN COUPLING FUSED-SILICA OPEN-TUBULAR COLUMNS IN GAS-CHROMATOGRAPHY

There are a number of parameters which have to be chosen depending on the analysis being done in gas chromatography. While the choice of sta tionary phase material is based on the solutes to be separated, the th ickness is dependent on the concentration and the volatility of the co mponents to be analyzed. This study undertakes a coupled column phase ratio optimization by connecting a short piece of a particular column prior to a normal length of an analytical column. Various columns of d ifferent dimensions (phase ratio), but of the same stationary phase ma terial (methyl silicone), are coupled together by a deactivated glass press-fit connector, and the efficiency and capacity are measured. The coupling of fused silica open tubular columns is optimized in efficie ncy by matching or decreasing the phase ratio of successive columns. C apacity optimization is accomplished by increasing the phase ratio of consecutive columns. Capacity and efficiency optimization are opposing each other; therefore, if some efficiency can be sacrificed a substan tial increase in capacity is possible.