JPH06121927A - Metallic ion trapping agent - Google Patents

Abstract

PURPOSE:To trap metallic ions and to effectively use this method for analysis or separation of metallic ions by constituting the metallic ion trapping agent trapping and recovering metallic ions in a soln. of an alkyl product of specified cyclic inulooligosaccharide, thereby simply coupling the agent with metallic ions. CONSTITUTION:Metallic ions in a soln. is trapped and recovered with a metallic ion trapping agent to separate and remove metallic ions from various compds. or mixtures. The metallic ion trapping agent consists of an alkylated product of cyclic inulooligosaccharide produced by partially or wholly alkylating hydroxyl groups of cyclic inulooligosaccharide having a cyclic structure of 6-8 molecules of fractose with beta-2,1 bond. The alkyl group of the alkylated product is a methyl group. The obtd. metallic ion trapping agent simply couples with metal ions to trap metal ions. Thus, the agent is useful for analysis and separation of metallic ions.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel metal ion scavenger comprising an alkyl compound of a specific cyclic inulooligosaccharide.

[0002]

2. Description of the Related Art Conventionally, many methods for separating and removing metal ions from various compounds and mixtures have been proposed. A typical example is a method of capturing and recovering metal ions in a solution by using a chelate compound. Further, a method of recovering metal ions by using cyclodextrin, which is known to form an inclusion compound, and a method of using various crown ethers are also well known.

The capture of metal ions by the use of chelate compounds is related to various factors such as the types of metal ions and ligands for forming chelate compounds, the size of chelate ring, and the like. There is a problem that it is difficult to select a chelate compound for. On the other hand, the cyclodextrin capture and recovery method has a problem that the capture action on metal ions is weak.

Further, the method using crown ether is as follows:
There are problems that crown ethers are very expensive and that the metals that can be captured are limited. Further, a metal composed of a cyclic inulooligosaccharide described in Japanese Patent Application No. 3-243819 (filed on Sep. 24, 1991), in which 6-8 molecules of fructose form a cyclic structure with β-2,1 bonds. Although there are examples of scavengers for ions, this compound is unstable and its scavenging effect is insufficient, and furthermore, when capturing metal ions in an aqueous solution, it is necessary to extract with an organic solvent, so an organic solvent There is also the problem of being insoluble in.

[0005]

Means for Solving the Problems The present inventors have found that a specific cyclic inulooligosaccharide alkyl compound is stable and has a property of easily binding to and capturing a metal ion,
The present invention has been completed. That is, the gist of the present invention is that a metal consisting of an alkyl derivative of a cyclic inulooligosaccharide obtained by alkylating all or part of the hydroxyl groups of the cyclic inulooligosaccharide in which fructose 6-8 molecule forms a cyclic structure with β-2,1 bonds. Exists in ion scavengers.

The present invention will be described in detail below. The alkyl form of the cyclic inulooligosaccharide used in the present invention is represented by the following formula (1) (hereinafter, may be abbreviated as “the present compound”), and the cyclic inulooligosaccharide of the following formula (2) is represented. Obtained by alkylation.

[0007]

[Chemical 1] (In the above formula, R represents a hydrogen atom or an alkyl group,
n represents an integer of 6 to 8. )

[0008]

[Chemical 2] (N has the same meaning as in formula (1).)

The cyclic inulooligosaccharide represented by the formula (2) is a known substance described in JP-A-2-252701,
The same publication or Japanese Patent Application No. 3-3983 (January 17, 1991)
As described in (Japanese Patent Application), for example, an enzyme that acts on a β-2,1-linked fructose polymer having a degree of polymerization of 8 or more to produce the present compound by an intramolecular transfer reaction, or an enzyme that produces the enzyme outside the cell A microorganism can be produced by acting on inulin.

For alkylating cyclic inulooligosaccharides, alkylating agents generally used for alkylating hydroxyl groups can be used. For example, methyl iodide, ethyl iodide, propyl iodide, butyl iodide, amyl iodide, octyl iodide, methyl bromide, ethyl bromide, propyl bromide, butyl bromide, amyl bromide, octyl bromide, Alkyl halides such as methyl chloride, ethyl chloride, propyl chloride, butyl chloride, amyl chloride and octyl chloride are preferably used.

Dialkyl sulfuric acid such as dimethyl sulfuric acid or diethyl sulfuric acid is also preferably used. Dialkyl carbonates such as dimethyl carbonate and diethyl carbonate are also preferably used. As the alkylation method, the above-mentioned alkylating agent is allowed to act on the cyclic inulooligosaccharide in the presence or absence of a solvent, but if the alkylating agent is present in excess with respect to the cyclic inulooligosaccharide, all the hydroxyl groups of the sugar are alkyl. Compounds are obtained, whereas less alkylating agents give partially alkylated compounds.

Next, a method for capturing metal ions using the present compound will be described. The metal ions captured in the present invention are not particularly limited, but heavy or light metals such as iron, copper, zinc, tin, antimony, nickel, chromium, manganese, lead, cadmium, silver, aluminum, lanthanum, and cobalt, lithium. , Sodium, potassium,
Examples thereof include alkali metal ions such as rubidium, cesium and francium, and alkaline earth metal ions such as beryllium, magnesium, calcium, strontium, barium and radium.

In the present invention, these trapped metal ions are generally used in the form of the metal, a salt thereof or another compound, and are supplied as a solution such as an aqueous solution or a water-organic solvent solution. Is contacted with the present compound as an ion. As the organic solvent when supplied as a water-organic solvent solution, lower alcohols such as methanol, ethanol, propanol, isopropanol and butanol; polar organic solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide and N-methylpyrrolidone are preferable, It is used as a mixture with water at an arbitrary ratio.

The scavenger of the present invention can be applied to, for example, analysis and separation of metal ions. Specifically, the compound is bound to a suitable carrier, and the solution containing the metal ion is brought into contact with the carrier. The captured metal ions are recovered by flowing out with an appropriate solvent used in ordinary chromatographic separation and the like.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 1 Deuterated methanol (CD ₃ OD) / heavy water (D ₂ O) =
Completely methylated cycloinulohexaose in a 0.1M solution of various metal salts of 7/3 (volume ratio) (the above general formula (1)
(R = methyl group, n = 6 compound) was added to the metal salt in a molar ratio of 1/10 to 1/20. After leaving at room temperature for about 1 hour, Varian NMR [UNI
TY-300 (300 MHz)] to measure this solution,
Induced shift of protons in the absence of metal salt (Δδ (pp
m)) and the induced shift difference of the proton in the presence of a metal salt were observed. According to the principle of NMR, the larger the induced shift, the larger the trapping action. The results are shown in Table 1.

[0017]

[Table 1] Table 1 ─────────────────────────────────── Metal salt induced shift difference (Δδ ( ppm)) ─────────────────────────────────── [Proton species] ^* 1A 1B 3 4 5 6A 6B ─────────────────────────────────── 1. NaCl -0.02 0.02 0 0.02 0.01 − − ─────────────────────────────────── 2. KCl − − 0.02 0.13 − − − ──────────────────────────────────── 3. CsCl -0.08 0.13 − − − − − ──────────────────────────────────── 4. BaCl ₂ · H ₂ O − 0.01 − − 0 − − ──────────────────────────────────── 5. Pb (NO ₃ ) ₂ 0 0.01 0 0.01 0.01 − − ─────────────────────────────────── * Each The proton species correspond as follows.

[0018]

[Chemical 3]

From these results, it can be seen that a complex is specifically formed with potassium ion and cesium ion.

COMPARATIVE EXAMPLE 1 A metal was captured in the same manner as in Example 1 except that cyclohexaose (n = 6 in the general formula (2) above) was used instead of the completely methylated cycloinulohexaose. I investigated the effect. The results are shown in Table 2.

[0021]

[Table 2] Table 2 ─────────────────────────────────── Metal salt induced shift difference (Δδ ( ppm)) ─────────────────────────────────── [Proton species] 1A 1B 3 4 5 6A 6B ─ ─────────────────────────────────── 1. NaCl − − 0.02 0.01 − − 0.01 ─────────────────────────────────── 2. KCl -0.08 -0.01 0.06 0.02 -0.08 0.06 0.01 ──────────────────────────────────── 3. CsCl -0.09 0.02 0.03 0-0.01-───────────────────────────────────── 4. BaCl ₂ · H ₂ O − − 0.19 0.12 − − − ──────────────────────────────────── 5. Pb (NO ₃ ) ₂ − − 0.24 0.11 − − − ────────────────────────────────────

From these results, it can be seen that non-alkylated cycloinulohexaose has a low ability to form a complex with potassium and cesium ions.

[0023]

The scavenger of the present invention is useful for the analysis and separation of metal ions because it can easily capture metal ions.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eri Hosono Sanyo Kasei Co., Ltd. Research Institute, 1000, Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa

Claims (2)

[Claims] 1. A metal ion trap comprising an alkyl compound of a cyclic inulooligosaccharide obtained by alkylating all or part of the hydroxyl groups of a cyclic inulooligosaccharide in which 6-8 molecules of fructose form a cyclic structure with β-2,1 bonds. Agent. 2. The metal ion scavenger according to claim 1, wherein the alkyl group of the alkyl compound is a methyl group.