Quality control column blank

An added elution step was used in this experiment to check the completeness of elution and the cleanliness of the resin. After sampling and elution of the resin (200 mL, 2 X 150 mL) with ethyl ether, the resin column was eluted with an additional 200 mL of ether, which was then concentrated to 1 mL for broad spectrum GC analysis. This fourth elution was a quality control blank for the subsequent reuse of the resin (Figure 2, top chromatogram). 

In a typical bench-scale study, five columns were set up under the strict quality control-quality assurance (QA-QC) requirements of this project one column for the control of reagents and glassware, one column for the control of the resin blank, and triplicate columns for model compound studies. 

Figure 3. Capillary GC profile comparison of resin cleanup procedures by ultrasonic bath and Soxhlet extraction. Y-axis 1E2 — 0.005 ng/L to 1 E4 = 0.5 ng/L. The resin was extracted with methanol, acetonitrile, and methylene chloride. Fifty milliliters of resin was placed in a column and eluted with 2 bed volumes (50 mL) of methylene chloride. The third bed volume was concentrated to 1 mL, and 2.5 pL was injected into the GC. This sample represents a sample elution quality assurance control blank.

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