Session chair: Gerard Rozing

Keynote Speaker: Vince Remcho, Oregon State University, Corvallis, OR, USA

Microcolumn HPLC Technology; 30 years (or more) development but still not routine

Since first commercial introduction of microbore HPLC technology by Hewlett Packard Company with the famous HP1090 model in the early eigthies, the technique has not come up to meet expectations. Performance, speed of analysis and detection sensitivity did not improve significantly. Matching the HPLC system volume to conserve the volume integrity of separated peaks was a too large challenge for many physical, and engineering reasons and was only partly achieved. The introduction of the first commercial CE systems did generate a new, strong hope that microcolumn separation, in this case on capillary columns, would have a breakthrought. After 10 years in the early 2000's CE has found it niche in the market but has not become a broad routine analysis technique. The new hype in liquid phase separations, microfluidic separation devices that where the eluent was driven by hydraulic pressure (HPLC chips) or by electric field (microchip electrophoresis) did excellent analytical tasks especially in bioanalysis but are closed systems designed to do one particular task very well.

A few fundamental barriers are at base of practical success for microcolumns or microchips viz. the growing unfavorable surface/volume ratio which will give rise to significant influence of the conduit surface on the separation mechanism rendering it less predicable and reproducible and mandating surface property manipulation. In addition a small volume separation device mandates sample volumes of 1-5% of its own volume and therefore in practice tolerates only nanoliter sample volumes.

Continuous development thus is mandatory for this field. In this session some of the barriers will be touched upon and dealt with.