Microcolumns open tubular capillary

Figure 8.1 Different types of microcolumns (a) open tubular capillary column (1-50 fim I.D.), (b) dry packed capillary column ( 200 jim I.D.), and (c) microbore column (0.5-1 mm I.D.), narrow-bore column (1-2 mm I.D.), and slurry packed capillary column ( 500 /xm I.D.). (Adapted from Ref. 2 with permission.)...

H. G. J. Mol, H.-G. Janssen, C. A. Cramers and U. A. Th Brinkman, On-line sample enrichment-capillary gas clir omatography of aqueous samples using geometr ically deformed open-tubular extraction columns , 7. Microcolumn Sep. 7 247-257 (1995). 

In a study presented by Jinno et al. [124], packed column capillary electrochromatography, open-tubular CEC, and microcolumn liquid chromatography using a cholesteryl silica bonded phase have been studied to compare the retention behavior for benzodiazepines. The results indicated that CEC was a promising method, as it yielded better resolution and faster analysis than microcolumn LC for benzodiazepines. Similar selectivity to HPLC was noted, except for a few solutes that were charged under the separation conditions. Columns packed with the ODS and cholesteryl phases were compared and showed totally different migration orders of the analytes. The retention on the cholesteryl silica sta-... 

Amperometric detectors are easily miniaturized with preservation of performance, since their operation is based on reactions at the electrode surface. Using a single carbon fiber or microelectrode as a working electrode allows detector cells of very small volume and in-column detectors to be constructed for use in open tubular and packed capillary column liquid chromatography [189-192]. These microcolumn separation techniques combined with amperometric detection are exploited for the quantitative analysis of volume-limited samples such as the contents of single cells [193,194]. 

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