Preparation of liquid mixtures

Patent metadata

Field	Value
Publication number	US-9446329-B2
Application number	US-98855309-A
Country	US
Kind code	B2
Filing date	Apr 20, 2009
Priority date	Apr 21, 2008
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

A method of determining the relative component proportions of at least one each of: a buffer; an acid or a base; a solvent; and optionally a salt, for providing a liquid mixture of pre-defined pH and ionic strength, wherein the relative component proportions are determined using the equation of Debye-Hückel, wherein the ion size parameter a in the Debye-Hückel equation is determined as the weighted mean ion size of all species contributing to the ionic strength of the liquid mixture, and wherein the ionic strength of each species is used as weighting parameter. The present method is also applicable in a method of providing a liquid mixture. Further there is provided a buffer preparation device.

First claim

What is claimed is:

1. A method for use with a system, the method comprising:
combining, by the system, a plurality of liquids to create a liquid mixture having predetermined pH and ionic strength, the combining including:
determining, by the system, the ion size parameter a in the Debye-Hückel equation based on the weighted mean ion size of all species contributing to the ionic strength of the liquid mixture, the ionic strength of each species being used as a weighting parameter in the Debye-Hückel equation;
determining, by the system, the relative component proportions of at least one of each of a buffer, an acid or a base, a solvent, and optionally a salt, based on the Debye-Hückel equation and the determined ion size parameter a; and
mixing, by the system, the components according to the determined relative component proportions to obtain the liquid mixture.

2. The method of claim 1 , wherein the relative component proportions are determined using an iterative procedure.

3. The method of claim 2 , wherein the iterative procedure includes:
(a) determining the relative component proportions wherein a predefined ionic strength of the liquid mixture is addressed to the species according to a predefined distribution among the species;
(b) on the basis of the relative component proportions determined in the preceding step, calculating the ionic strength of each species in the mixture;
(c) determining a new set of relative component proportions;
taking account of the ionic strength calculated in (b), and (d) repeating the steps (b) and (c) until a predetermined convergence criteria is met.

4. The method of claim 3 , wherein, in step (a), the predefined ionic strength of the liquid mixture is addressed to the salt.

5. The method of claim 1 , wherein the ion size parameter a of the Debye-Hückel equation is determined as

a
=

∑

⁢

I
i

⁢

a
i

⁢

I

wherein I i is the ionic strength and a i of species i, and I the total ionic strength.

6. The method of claim 1 , wherein the ion size parameter a in the Debye-Hückel equation is approximated as a=0.5*(mass) 1/3 +shell.

7. The method of claim 6 , wherein “shell” is fixed at one value for a positively charged species and fixed at a different value for a negatively charged species.

8. The method of claim 6 , wherein “shell” is fixed at a value in the range of 3.8-4.2, for positively charged ionic species.

9. The method of claim 6 , wherein “shell” is fixed at a value in the range of 0-0.2 for negatively charged ionic species.

Assignees

• Bjorkesten Lennart
• Carredano Enrique
• Malmquist Gunnar
• Rodrigo Gustav
• Stafstrom Nils
• Ge Healthcare Bio Sciences Ab

Inventors

• Bjorkesten Lennart
• Carredano Enrique
• Malmquist Gunnar
• Rodrigo Gustav
• Stafstrom Nils

Classifications

• B01D15/166

  Fluid composition conditioning, e.g. gradient · CPC title

• B01D15/12 Primary

  relating to the preparation of the feed · CPC title

• G01N30/34

  of fluid composition, e.g. gradient (G01N30/36 takes precedence) · CPC title

• G01N2030/347

  mixers · CPC title

• B01D15/361

  Ion-exchange · CPC title