Reversed-phase liquid chromatography inverse

Decrease in particle size results in increased column efficiency. In preparative chromatography, in practice it is not possible to increase the column efficiency indefinitely, for both practical and economical reasons. Pressure drop is inversely proportional to the square of the particle diameter. Ease of packing of columns decreases with decreasing particle size. Current average particle sizes for reversed-phase PHPLC are in the range of 7-20 p,m. In preparative liquid carbondioxide-based SFC, smaller particles in the 5-10 p.m range are used due to the low viscosity of the mobile phase. 

---