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Chapter 8 Liquid Chromatograph. 8.1 Introduction. High pressures. High speed. High performance. High sensitivity. 8.2 Principles. 1.Classification. (1)Liquid – Solid chromatography. Adsorption process. X m + n S a X a + n S m. (2) Liquid – Liquid Chromatography.
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Chapter 8Liquid Chromatograph 8.1 Introduction High pressures Highspeed High performance High sensitivity
8.2 Principles 1.Classification (1)Liquid – Solid chromatography Adsorption process Xm + n Sa Xa + n Sm
(2) Liquid – Liquid Chromatography Partition Process Xm Xs
(3) Ion Exchange Chromatography X+ + Y(resins) Y+ + X(resins)
(4) Ion pair Chromatography X+a + Y- aX+ Y- org
2. Column efficiency of LLC Eddy diffusion Longitudinal diffusion
3. Separation of Components (1)Resolution R 7-19 (2)Separation Factor 7-20
4. Separation Equation of LC Assume:Y1=Y2=Y, k1≈k2=k 7-21 7-22 8-23
5. Factors affect Resolution of a column (1) Plat number n = f ( L,H ) H=f (u,k,Dm,Ds, ….) (2) capacity factor k=p/q P,q relay to mobile & stationary phase (3) Selectivity factor α=k2/ k1
8.3 Instrumentation of LLC 1. LLS System (1) Reservoirs (2) Pump (3) Sample Injection Port (4) Column (5) Detector
2. stationary phase Porous micro beads support Pellicular micro beads support 3. mobile phase (solvent) Polarity order N-Heptane < … < water