1987 Volume 36 Issue 3 Pages 154-158
Optimization of column parameters, namely the flow rate of carrier gas and temperature program rate for a determination of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) and 2, 3, 7, 8-tetrachlorodibenzofuran(TCDF) were performed using fused silica capillary column gas chromatograph connected with mass spectrometer. Using homologues of straight chain alkanes(C12C24), separation numbers (TZ value) were determined at eight different average linear velocity of carrier gas and temperature program rate of 4 °C/min. The experimental results elucidated the over view of a change of separation efficiency through the wide range of elution temperatures and flow velocity of carrier gas. It was suggested that flow velocity and column temperature should be controlled for the improvement of separation efficiency. The resolution (R) between closely eluting TCDD isomer (1, 4, 7, 8-TCDD) and 2, 3, 7, 8-TCDD was adopted as a parameter of separation. The average linear velocity of 40 cm/s was found optimum in case of using Supelco SP-2331 fused silica capillary column (60 m×0.32 mm i.d., 0.2 μm film thickness). The resolution of 2, 3, 7, 8-TCDD under the optimum flow velocity was examined at six different temperature program rate (1, 2, 3, 5, 7 and 10°C/min), and the temperature program rate of less than 3°C/min provides good resolution of the isomer at the separation of 6σ or larger. Under the optimized operation condition of GC/MS, relative standard deviation of determination for 2, 3, 7, 8-TCDD in sludge sample was 3.7%, and the detection limit was 0.02 ng/g dry wt.
