Injection length

Dispersion depends on several experimental factors, such as volume of sample injected, length, inner diameter, and geometrical configuration to the space of the transportation tube [and the reactor(s), if there is any], and flow rate of the carrier. If all other variables are constant, then dispersion depends on the following parameters [8] ... 

Fig. 6 Simulation of concentration distribution in frontal analysis capillary lenth 50 cm injection length 12.5 cm, corresponding 245 nL at 50-/j,m i.d. of capillary association constant 5000 M 1 initial concentration substrate 0.11 mM, ligand 0.1 mM mobility of substrate 10, of complex 40, of ligand 40 X 10-5 cm2V 1 B is 50 seconds after application of 25 kV.

Fig. 7 Same conditions as in Fig. 5, but injection of 0.1 mM solution of ligand into the substrate-containing buffer, injection length 1.5 mm.

In practice, the width of the initial sample pulse should be less than 1% of the total length of the capillary. However, at very small injection lengths, the amount actually injected is dominated by mixing at the interface between the capillary and the sample solution. The minimum injection length for a capillary with 75 gm I.D. has been estimated at approximately 200 /Am,17 although typical injection lengths are 5-10 times longer. 

For small injection lengths the peak widths are determined by diffusion. For large injection lengths, peak widths are determined by two times the square root of the variance of the injection length. 

Pyell and Rebscher [30] proposed that the injection length in CEC for neutral compounds is... 

Nucleosil 100 Cl8 (3 pm) Peak width vs. injection length /2Peak width vs. volume fraction of water in sample solution... 

Fig. 4 Le/i PMMA-based 2D electrophoresis chip made for the multidimensional separation of proteins using SDS p-CGE and MEKC. The solution reservoirs were a) sample reservoir, (h) sample waste reservoir, (c) SDS p-CGE buffer reservoir, d) SDS p-CGE buffer waste reservoir, (e) MEKC buffer reservoir, if) MEKC buffer waste reservoir. SDS p-CGE channel Injection length 10 mm, separation length 40 mm, effective separation length = 30 mm MEKC channel separation length 25 mm, effective separation length 10 mm. Right. 2D separation of a fecal calf serum proteome using SDS p-CGE/MEKC. The 2D SDS p-CGE x MEKC were performed at 300 V/cm and 400 V/cm, respectively. A 10 s separation time was utilized in the first dimension prior to performing the serial 10 s MEKC cycles. A total of 159 MEKC cycles was used with a 1 s transfer time from the first to second dimension. All of the proteins were labeled with a fluorescent dye prior to the separation. Reprinted with permission from Shadpour and Soper [81] and Osiri et al. [82]...

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