Retention of Solids in Rotating Coiled Columns: The Effect of β Value and Tubing Material

Abstract

The retention behavior of suspended solids in rotating coiled columns (RCC) has been studied. It has been shown that the greater the β‐value (ratio of rotation and revolution radii) the better the retention of solid matter. It has also been shown, that up to five grams of a polydisperse soil sample are completely retained in PTFE columns with a total inner capacity of 34 mL (3.2 mm tubing bore) for a wide range of experimental conditions (column rotation speed and mobile phase flow rate). The successful demonstration of the scale‐up of solid suspension retention in RCC, will enhance the capabilities of the accelerated dynamic sequential extraction of trace elements (TE) and other organic and inorganic solutes from solid samples. This will not only be possible for the analysis of samples with elevated TE concentrations, but also for those with slightly elevated or “normal” TE concentrations. PTFE coiled columns have been found to be preferable to stainless steel ones.

Keywords:

• Countercurrent chromatography
• Rotating coiled columns
• Retention of solid particulate
• Fractionation
• Extraction from solids

Acknowledgments

This work was supported by the European Union INTAS (grant N 00‐00782). The authors would like to thank Lee Janaway of Brunel Institute for Bioengineering for his help in constructing a set of constant β PTFE columns.