Why use short(er) columns? ...

... High Speed HPLC with short columns offers numerous advantages and benefits:
redball.gif (924 Byte) short analysis time - only 1/7 of standard HPLC pfeil-rot.gif (990 Byte) high sample through-put, i.e. tremendously reduced costs per analysis
redball.gif (924 Byte) low solvent consumption - only 1/5 of standard HPLC pfeil-rot.gif (990 Byte) cost saving + improved environmental compatibility
redball.gif (924 Byte) decreased diffusion /dispersion pfeil-rot.gif (990 Byte) increased sensitivity - > 2-fold -
redball.gif (924 Byte) increased performance, i.e. minimum band broadening- pfeil-rot.gif (990 Byte) higher number (N) of hight equivalents of theoretical plates (HETP) per meter - > 4.5-fold -

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Stationary phase: GROM SIL 100 ODS-2 FE; Linear velocity: 0.8 mm/s; Eluent: ACN:H2O = *65:35, resp. **60:40; Flow cell: 1.2 Ál / 3 mm with quick-connector (100 x 0.1 mm capillary); Injection: 5 Ál benzoate test mixture / 1:100 dil. (methyl-, ethyl-, propyl-, butyl-, pentyl benzoate; 10-20 mg/ml)
Varying column length and particle size can substantially reduce runtimes and solvent consumption without compromising sensitivity or resolution
    
Column Length
Particle Size
AnalysisTime
[min]
Solvent Consumption
[ml]
Sensitivity
(1st peak ) [AU]
Resolution
(1. + 2nd peak)
N/m
(5th peak )
250 x 4 mm *
10 Ám
18.1 10.9 0.004 4.8 29 000
125 x 4 mm *
5 Ám
9.4 5.6 0.008 5.2 72 200
60 x 4 mm **
3 Ám
4.8 2.9 0.013 4.6 129 300
33 x 4.6 mm *
1.5 Ám
2.5 2.0 0.010 2.5 130 900