Eluent programme

Fig 9a-c. Eluent programme eab(V) (eluent hexane-methylethyl ketone) (a) theoretically calculated (b), and experimental (c) chromatograms of poly(diethylene glycol adipate) of M = 550, f = 1.63 6S)... 

Fig. 24. Examples of the effect of eluent programme s>h(V) on retention volumes of macromolecules of different functionality (calculated data for D = 8,N = 10,Xq = 3.6,Xq, = 5.6, V0 = Vp = 40ml, verical lines in the figure correspond to retention volumes of macromolecules of different functionality)...

The theoretical considerations discussed briefly above have been further enlarged and the enhanced calculation of optimal gradient programmes was achieved involving three factors gradient slope, initial eluent composition and gradient curvature. In the case of an ACN organic modifier the retention of an analyte can be described by... 

Fig. 1.22. Direct injection of aluminium processing solution. Conditions Supelcosil LC-18-DB column gradient programme at a flow-rate of 1.0 ml/min from 1.05 M HIBA to 0.4 M HIBA over 10 min. and held at 0.4 M for 5 min. modifier, 1-octanesulphonate at 0.01 M (A), eluents at pH 4.5 (B), eluents at pH 3.8 detection at 658 nm after post-column reaction with Arsenazo III sample injected, 50 pi sample dilution, (A) 10 ml to 100 ml,...

HPLC Analytical RP-HPLC was performed using a Phenomenex Jupiter Cig (250 X 4.6 mm, 5 pm, 300 A) reverse phase column and a Waters system composed of No. 600 pump, No. 600 controller, and No. 490 programmable multiwavelength detector (Nihon Waters, Tokyo, Japan). Eluent A was 0.1% TFA in water and eluent B was 0.1% TFA in acetonitrile-water (80 20, v/v). A linear gradient of eluents (0-90% B in 45 min) with a 1 mL/min flow rate was used as the mobile phase. Three different wavelengths were applied for the detection of peaks (k = 214, 254, and 280 nm). 

The analysis is started with the guard column and separation column in series. After about 3 min, the valves, controlled by the detector programme, switch over such that the eluent flows past the guard column, direct to the separation column. The columns are switched at a point when the components to be determined, but not the interfering matrix, have reached the separation column. After about 35... 

Chromatographic separations were made by using a MERCK LaChrom HPLC system equipped with a LiChrospher 100 column filled with 5- Um RP-18 packing material (125 mm x 4 mm) and with a programmable UV detector. Samples (10 lA ), injected by the autosampler, were eluted as follows. Isoproturon eluent 60%... 

Sander and Field (16) used a liquid chromatograph (solvent programmer in conjunction with two pumps) to generate a mobile-phase gradient. The eluent was introduced into the developer trough and distributed across the layer. 

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