The Introduction of the theory in GFFF ,mainly about the HLF(hydrodynamic lift force) and viscosity influence. Lvbo 20120411. Introduce. The FFF(field flow fractionation):the concept of field and flow . GFFF: Particles >1 µm. Applicable to water and organic solvents
The Introduction of the theory in GFFF ,mainly about the HLF(hydrodynamic lift force) and viscosity influence
The FFF(field flow fractionation):the concept of fieldand flow.
Particles >1 µm. Applicable to water and organic solvents
The simplest design of all FFF methods
The cheapest and the most basic
Constant gravity field
Do not damage to the sample and keep
the integrity of the structure and function of them
micrometer-sized particles: coal particles,silica particles,clay particles,starch granules,yeast,and pollens.
Biological: lymphocytes,red blood cells,parasites,stem cells,and bacteria…….
雷诺系数<2000 Parabolic flow shape
ν0=0.833/100 m/s (2ml/min)
r =6*10-6 m
Stress Analysis,then theory contains G、HLF、and so on.
From v to R or inverse.
Change conditions to test the S or H and resolution.Both theory and the actual.
1.Drag or Adsorption.
3.Rotate when flowing
d 与tr 成反比，与R成正比
粒子多分散性 sample poly-dispersity
边缘效应 edge eﬀects
进样体积 sample volume
柱后效应 extrachannel volumes
终端效应 channel end
r=6 um HLF(hydrodynamic lift force) and viscosity influence、w=200um、v02ml/min、254nm。。。。。。
1.Both up and down mode ,the R gradually increased with the channel angle for each of the carrier liquids.
2.Ideal steric FFF:R=6r/w(0.18)
only in the case of B1, the lowest viscosity solution do the observed
R <=0.18 and γ <1.
3. There does no signiﬁcant diﬀerence in R for upward and downward
4.The diﬀerent R of A and B indicates that viscosity is not the only factor inﬂuencing lift force. The
lower ionic strength of A for higher R .
H inj=0.0026 cm
The polydispersity contributions are similarly small as H inj and HB
1.As the carrier viscosity increases,HLF increase,so the HLF(hydrodynamic lift force) and viscosity influenceR increasse for both A and B system.
2. The important observation is that analysis times decrease without loss of resolution.
3. Peak symmetry improves(HLF lifting of the particles away from the channel wall),so the resolution do not decrease very much.
2. The zone broadening is apparently not strongly inﬂuenced by carrier
viscosity so that the analysis times may be reduced without loss of resolution.
3. the contributions to H due to sample volume, sample polydispersity, and Brownian motion have been shown to be small compared to
the measured plate heights.
Thank You ! HLF(hydrodynamic lift force) and viscosity influence