Capillaries conditioning

Capillary conditioning rinsing with 0.1 M sodium hydroxide for 30 minutes. Then it is... 

Figure 5.11 Schematic diagrams of the FASS model, (a) Capillary conditioned with a BGE, sample, injection and a high positive voltage, (b) focusing of analytes near the boundaries between the sample zone and BGE, and (c) stacked analytes separated [97].

Fig. 10.26. Separation of some likely components found in commercial tetracycline. (A), Bare capillary with buffer pH 3.0 (30 mM citric acid and 24.5 mM P-alanine) 500 mm x 50 pm i.d. 30 kV, electrokinetic injection for 5 s at 10 kV (B), bare capillary, same as for A but with buffer-methanol (60 40 v/v) (C), Hydride (etched) capillary 250 mm x 50 pm i.d., other conditions same as for B (D), Cl8 etched capillary, conditions same as for C. Peak identification 2, tetracycline 3, chlorotetracycline a, 4-epitetracycline b,...

The possibilities of the Poiseuille equation for explaining capillary phenomena in soils have had a certain amount of appeal to soil physicists. The theory of capillarity is so simple and so well established that if suitable soil parameters to express a bundle of capillaries could be found, the problem would be solved in the most direct fashion. Unfortunately, however, there has as yet been no completely satisfactory formula for the capillary bundle theory, although it has often given results of the proper magnitude in certain instances. We shall here develop the Poiseuille equation for special capillary conditions and point out the fallacies of this approach. 

Figure 22 Electropherograms for the Lys-C digest of transferring on (A) etched and (B) unetched capillaries. Conditions 50 mM phosphate buffer, pH 3.0 field 300 V/cm temperature, 28°C /, 56 cm. (Reprinted from Ref. 99, with permission.)...

Figure 23 Separation of a cytochrome c mixture on 50-pm-i.d. capillaries (A) bare capillary (B) etched cholesteryl-modified capillary (C) etched cyanopentoxy-modified capillary. Conditions V= 15 kV and mobile phase 100% aqueous pH 3.0 buffer (60 mM citric acid and 50 mM (f-alanine). Dimensions cholesteryl capillary, L= 70 cm and /= 45 cm. Bare and cyanopentoxy capillaries, Z.= 50 cm, and /= 25 cm. Solutes 1, chicken 2, tuna 3, horse 4, bovine. (Reprinted from Ref. 102, with permission.)...

Figure 34 Separation of dansylphenylalanine on MIP CSP. (a) Silicate-entrapped CEC capillary. Conditions i.d., 75 pm 7tot 25 cm Z.eff 17 cm applied potential 30 kV electrokinetic injection, 10 kV for 10 s UV detection at 280 nm, mobile phase is 80/20 acetonitrile/100 mM acetate (pH 3.0). (b) HPLC separation. Conditions column, 15 cm x 0.46 cm 1.0-mL/min flow rate, 2% acetic acid in acetonitrile, 30-pL injection, UV detection at 280 nm. (Reprinted from Ref. 20, with permission.)...

Rinsing with 1 M NaOH (10 min), water (10 min), and running electrolyte (15 min) Capillary conditioning ... 

Figure 4.9 Electrochromatographic separation of benzene derivatives on the seiected monolithic capillary. Conditions capillary column lOOppm ID x 30cm active length stationary phase 0.3mol% of 2-acrylamido-2-methyl-1-propanesulfonic acid in monomer mixture pore size 750 nm (1) thiourea, (2) benzyl alcohol, (3) benzaldehyde, (4) benzene, (5) toluene, (6) ethylbenzene, (7) propylbenzene, (8) butylbenzene, (9) amylbenzene. (Reprinted from [396] with permission of the American Chemical Society).

Capillary conditions these are affected by the capillary pretreatment reagents (e.g., NaOH) or dynamic capillary coating systems to achieve better reproducibility. 

Figure 6 SEM of silica monolithic CEC column inside a fused silica capillary. Conditions - fused silica ID 75 pm the monolith was prepared by the procedure described by Ishizuka N, Kobay-ashi H, Minakuchi H, et at (2002) Journal of Chromatography A 960 85-96. (Courtesy of Mr. J. Hutchinson.)...

Table V shows thermally generated Maillard reaction products with medium and low volatility isolated from the tomato products by extraction with methylene chloride and cleaned up by gel chromatography. They were separated on a 60 m fused silica capillary (conditions as for the volatile compounds listed in Table IV).

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