Stationary liquid Capillary wall Stationary phase
Stationary liquid Capillary wall Stationary phase
Relationship of K and k ● K refers to concentration ratio and k mass ratio K and k depends on thermodynamic properties of the components and stationary phase, Tc(柱温），Pc(柱压） ● K only relys on properties of the component and double phases, but not phase ratio. But k relys on not only properties of the component and double phases, but also phase ratio( amount of stationary phase) ● With a given chromatographic system, separation of the components is determined by relative amount of the components in both phases, but not relative concentration. The bigger k value, the longer rotention time, the easier separation. k =0 corresponds to dead time tM
Relationship of K and k ● K refers to concentration ratio and k mass ratio K and k depends on thermodynamic properties of the components and stationary phase, Tc(柱温），Pc(柱压） ● K only relys on properties of the component and double phases, but not phase ratio. But k relys on not only properties of the component and double phases, but also phase ratio( amount of stationary phase) ● With a given chromatographic system, separation of the components is determined by relative amount of the components in both phases, but not relative concentration. The bigger k value, the longer rotention time, the easier separation. k =0 corresponds to dead time tM
Ratio of the velocity of carrier gas and the component in column: Rs = uS /u = w = mM / (mS + mM) =1/(1+mS / mM) = 1/(1+k) Where u refers to velocity of carrier gas in column in unit of cm.s-1 , u velocity of the component in column, w mass fraction. ●Retardation factor(滞留因子, Rs）：
Ratio of the velocity of carrier gas and the component in column: Rs = uS /u = w = mM / (mS + mM) =1/(1+mS / mM) = 1/(1+k) Where u refers to velocity of carrier gas in column in unit of cm.s-1 , u velocity of the component in column, w mass fraction. ●Retardation factor(滞留因子, Rs）：
Defining L as column length, following formula are vivid: tR = L / uS tR = L /uS = tMu /uS = tM u / uS = tM(1+k) k = (tR -tM) / tM = t’R / tM tM = L / u Above equation can be employed to evaluate k value
Defining L as column length, following formula are vivid: tR = L / uS tR = L /uS = tMu /uS = tM u / uS = tM(1+k) k = (tR -tM) / tM = t’R / tM tM = L / u Above equation can be employed to evaluate k value
2.2.1Basic theory of chromatographic separation ●Partition of different components in double phases Depending on partition coefficient, molecular structure and properties of the components, stationary phase, mobile phase. Characterized by rotention value (rotention time or rotention volume), thermodynamic controlled. ●Movement of different components in column Depending on mass transfer(传质) resistance of different components in stationary phase and mobile phase. Characterized by peak width at half-height, kinetic controlled
2.2.1Basic theory of chromatographic separation ●Partition of different components in double phases Depending on partition coefficient, molecular structure and properties of the components, stationary phase, mobile phase. Characterized by rotention value (rotention time or rotention volume), thermodynamic controlled. ●Movement of different components in column Depending on mass transfer(传质) resistance of different components in stationary phase and mobile phase. Characterized by peak width at half-height, kinetic controlled