EP0424672A1
Expired / Lapsed
EP
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Method of removing endotoxin
Assignee: Kurita Water Industries Ltd
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Filing: 1990-09-20
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Granted: —
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Expires: 2010-09-20
Abstract
Abstract An endotoxin adsorbent prepared by crosslinking a porous granular chitosan obtained by dispersing an aqueous acidic solution of chitosan into a hydrophobic dispersant and evaporating water under stirring. A method of removing endotoxin from a solution containing only endotoxin as a absorbed material, wherein the pH value of the solution is adjusted to pH 9 or lower than it, and subsequently, the solution is passed through a column packed with a crosslinked granular chitosan. A method of removing endotoxin from a solution containing a protein and endotoxin as absorbed materials, wherein the pH value of the solution is adjusted to equal to or lower than the isoelectric point of the protein and, subsequently, the solution is passed through a column packed with a crosslinked granular chitosan.
Inventors
- 👤 Tsuneyasu C/O Kurita Water Ind. Ltd. Adachi
- 👤 Junichi C/O Kurita Water Ind. Ltd. Ida
- 👤 Masanori C/O Kurita Water Ind. Ltd. Hashimoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 07:02
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0024; C08B37/0027; C08B37/003; B; B01; B01J; B01J20/00; B01J20/22; B01J20/24
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
28 words
(1) An endotoxin adsorbent prepared by crosslinking porous granular chitosan obtained by dispersing an aqueous acidic solution of chitosan into a hydrophobic dispersant and evaporating water under stirring.
Claim 2
Dependent Claim
23 words
(2) As adsorbent as defined in claim 1, wherein the hydrophobic dispersant is a compound having a boiling point of 100°C or higher.
Claim 3
Dependent Claim
21 words
(3) As adsorbent as defined in claim 1, wherein the hydrophobic dispersant is a compound capable of azeotropically boiling with water.
Claim 4
Dependent Claim
35 words
(4) As adsorbent as defined in claim 1, wherein the stirring is conducted under the conditions of a number of rotation from 300 to 5,000 r.p.m. and a peripherical velocity of 1 to 20 m/sec.
Claim 5
Dependent Claim
38 words
(5) As adsorbent as defined in claim 1, wherein the amount of a crosslinking reagent used in the crosslinking reaction is from 0.2 to 0.8 equivalent amount based on one equivalent amount of amino groups in the chitosan.
Claim 6
Dependent Claim
35 words
(6) As adsorbent as defined in claim 1, wherein the adsorbent has an ion exchange capacity of from 0.01 to 0.5 meq/ml and specific surface area of from 1 to 250 m²/g-dry crosslinked chitosan weight.
Claim 7
Dependent Claim
45 words
(7) A method of removing endotoxin from a solution containing only endotoxin as an abosrbed materials, wherein the pH value of the solution is adjusted to pH 9 or lower, and subsequently, the solution is passed through a column packed with a crosslinked granular chitosan.
Claim 8
Dependent Claim
49 words
(8) A method of removing endotoxin from a solution containing protein and endotoxin, wherein the pH value of the solution is adjusted to equal to or lower than the isoelectric point of said protein and, subsequently, the solution is passed through a column packed with a crosslinked granular chitosan.
Claim 9
Dependent Claim
44 words
(9) A method as defined in claim 7 or 8, wherein the crosslinked granular chitosan is obtained by dispersing an aqueous acidic solution of chitosan into a hydrophobic dispersant and evaporating water under stirring and by crosslinking porous granular chitosan with a crosslinking regent.
Claim 10
Dependent Claim
28 words
(10) A method as defined in claim 7 or 8, wherein the crosslinked granular chitosan is obtained by granulating a low molecular weight chitosan and then by crosslinking.
Claim 11
Dependent Claim
36 words
(11) A method as defined in claim 10, wherein the low molecular weight chitosan has an molecular weight of 10,000 to 500,000 prepared by deacetylating chitin with a deacetylating degree of from 50 to 100 mol%.
Claim 12
Dependent Claim
27 words
(12) A method as defined in claim 8, wherein the pH value is lower by 0.5 or more as compared with the isoelectric point of the protein.
Claim 13
Dependent Claim
57 words
(13) A protein solution containing endotoxin at low concentration of less than 100 pg/ml and a protein obtained by bringing the solution containing endotoxin and protein the pH of which is previously adjusted to equal to or lower than an isoelectric point of said protein solution into contact with a crosslinked granular chitosan packed in a column.
References Cited (Backward Citations)
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