| Popis: |
In open-tubular liquid chromatography (OTLC), elevation of the column temperature has the same effect as reductilon of the column diameter in obtaining high column efficiencies, with the additional benefits of easier column handling and fewer problems with detection. On an experimental set-up with commercially available 50 and 100 μm I.D. reversed-phase columns working in the 100–200°C range, all the advantages predicted by OTLC theory for elevated column temperatures were confirmed: smaller slope of the plate height vs linear velocity ( H vs. u ) curve, higher optimum linear velocity ( u opt ) value and less pronounced influence of the retention on efficiency. High-temperature operation makes high-efficiency and high-speed OTLC analysis feasible. On a 19.6 m × 50 μm I.D. SB-Methyl-100 column operated at 200°C with acetophenone as the test sample, 1 143 000 theoretical plates were obtained within 50 min. |
