Elution operation

The adsorption operation was conducted by feeding 1 mM phosphate solutions to the conditioned column at SV 10 or 20 h 1, and then 20 BV of water at SV 3 h 1. The elution operation consisted of feeding 0.1 M NaOH solution (80 BV) and then 20 BV of water at a flow rate of SV 3 h1. The regeneration of the column was conducted by feeding 0.5 M sulfuric acid (20 BV) and 20 BV of water at SV 10 h"1. All column effluents including washings in the adsorption and elution operations were collected on a fraction collector, and concentrations of phosphorus and zirconium in each fraction were determined by ICP-AES. Volume of each fraction was 5 BV for the adsorption operation and 4 BV for the elution operation. However, column effluents in regeneration operations were not analyzed. 

The only difference from the method (i) was in the regeneration operation. Here, the regeneration operation was conducted by supplying 0.5 M sulfuric acid (5 BV), 0.5 M sulfuric acid containing zirconium sulfate at 0.01 M (10 BV), 0.5 M sulfuric acid (15 BV) and water (20 BV) in successive at SV 10 h1. The adsorption and elution operations were almost the same as those in the method (i). 

Lead(II) adsorbed on both columns was quantitatively eluted with ca. 6 bed volumes of 1 M nitric acid. In this work, 2 cylcles of the adsorption-elution operation were repeated at each flow rate. Then 16 cycles of the adsorption and elution operation were conducted for each column. In the case of FPS-f column, averaged recovery was 104% with standard deviation (sd) of 4 % (n = 16) and for the other column, averaged recovery 103% with sd of 4 %. Table 3 summarizes numerical data for results shown in Fig. 4. Breakthrough capacities at C/Co = 0.05 are 0.54 - 0.57 and 0.28 - 0.33 mmol/g for FPS-f and FP columns, respectively. Total uptake was 0.78 -0.83 mmol/g for FPS-f and 0.51 - 0.54 mmol/g for RF-f. During repeated adsorption-elution operations, no deterioration of both RFP-f and FP-f was observed. 

Usually, the supply of the feed solution is stopped when the ratio of the adsorbate concentration in the effluent to that in the feed has reached a predetermined value (the break point ). Then, in the elution operation the adsorbate bound to the adsorbent particles is desorbed (i.e., eluted) by supplying a suitable fluid (eluent) that contains no adsorbates. In this way, adsorbent particles are regenerated to their initial conditions. However, in some cases the column may be repacked with new adsorbent particles. 

The adsorption and elution operations that the biosolute(s) undergo as they proceed along the column bed can thus be considered as a series of diffusion, convection, and reaction steps. In the adsorption process, the solute(s) in the feed must diffuse through a liquid film surrounding... 

Gradient elution operation is a usefid mean to suppress the band broadening and to increase the number of sample compounds separated and should be apphed, if possible, in both dimensions. Fig. 6 shows an example of comprehensive LC X LC separation of natural antioxidants with... 

Since the initial solute band on top of the column (very near z = 0) is a very thin one, we will ttssume that all of the solute species i (m,- moles) introduced via the feed sample are essentially located at z = 0 at the start of solvent elution operation (t = 0) therefore, at t = 0,... 

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