RU2275916C1 - Enterosorbent for heavy metal excretion - Google Patents

Abstract

FIELD: medicine, food processing industry.

SUBSTANCE: claimed enterosorbent contains 45-80 mass % of polysaccharide and balance: boehmite. As polysaccharide enterosorbent contains chitosan or lignin, or microcrystalline cellulose. Enterosorbent of present invention is useful in excretion of toxic substances from organism, prophylaxis of heavy metal intoxication, etc.

EFFECT: enterosorbent with high adsorption ability in relation to heavy metal ions; application only one kind of polysaccharide.

2 cl, 1 ex, 3 tbl, 2 dwg

Description

The invention relates to medicine, to the food industry (biologically active additives) and is intended to remove toxic substances from the body, to prevent poisoning by heavy metal ions, etc.

Known composite enterosorbent (RF patent for the application No. 2002120546, IPC 7 A 61 K 35/78, publ. March 20, 2004) containing a powder mixture of six components in the following ratio, wt.%:

Hydrolysis lignin 25.0-35.0 Microcrystalline Cellulose (CMC) 25.0-35.0 Fine silicon dioxide 25.0-35.0 Pectin 4.0-6.0 Starch 2.0-4.0 Calcium or Magnesium Stearate 0.5-1.0

The main disadvantage of the composite enterosorbent is the low adsorption capacity with respect to cations (not more than 60%) and anions (32%) of heavy metals (as follows from the following table 2). In addition, it includes four types of polysaccharide species in a predetermined quantitative ratio, which necessitates the acquisition of each of them and their use in the preparation of enterosorbent in the required amount of each.

Closest to the proposed solution is the gel solution of chitosan chosen by us for the prototype (RF patent No. 2175234, IPC 7 A 61 K 35/56, publ. 10/27/2001), prepared in a 1% solution of acetic acid, which is used in a method for removing lead and nickel from the body of animals.

The main disadvantage of the known solution is the low adsorption capacity with respect to heavy metals. So, for example, the experiments showed that the gel solution of chitosan reduces the content of the chromate ion (CrO ₄ ^2- ) in the solution by 88%, i.e. lower than the proposed enterosorbent by 12%.

The main technical result of the proposed invention is a high adsorption capacity with respect to heavy metal ions up to 100% (Tables 2 and 3). In addition, for the preparation of this enterosorbent, it is sufficient to use only one type of polysaccharide.

The specified technical result is achieved in that the enterosorbent containing the polysaccharide, according to the proposed solution, additionally contains boehmite in the following ratio of components, wt.%:

Polysaccharide 45-80 Boehmite Rest

In addition, as a polysaccharide, the proposed enterosorbent contains chitosan, or lignin, or microcrystalline cellulose.

The analysis of the prior art by the applicant made it possible to establish that there are no analogs characterized by sets of features identical to all the features of the claimed enterosorbent. Therefore, the claimed invention meets the condition of patentability "novelty."

Search results for known solutions in this and related fields in order to identify features that match the distinctive features of the prototype of the claimed invention have shown that they do not follow explicitly from the prior art.

From the prior art determined by the applicant, the influence of the transformations provided for by the essential features of the invention on the achievement of the indicated technical result is not known. Therefore, the invention meets the condition of patentability "inventive step".

An example of a specific implementation.

On the day of receipt of the declared enterosorbent, 1.5 g of polysaccharide, namely, lignin in the form of the preparation Polyphepan (Polyphepanum) manufactured by Ecosphere LLC, Veliky Novgorod, P.80 / 1211/3, was soaked in 400 ml of water for 3.5 hours to form gel solution. A drop of the solution was examined using a JEM 100 CXII transmission electron microscope (Japan). An electronic photograph is shown in figure 1. Boehmite was obtained by the interaction of aluminum powder with water in a slightly alkaline environment. For this, 0.45 g of aluminum powder (GOST 5494-95) and 2 ml of concentrated NH ₄ OH solution were added to the obtained gel solution to create an alkaline environment. The resulting mixture was heated to 50 ° C and left until the reaction of aluminum powder with water was complete. Then the resulting mixture was filtered on a Buchner funnel using a water jet pump, washed to a neutral pH. The enterosorbent precipitate was dried at 50-75 ° C, and then sterilized in an oven at 160 ° C for 1 hour. The resulting enterosorbent was also examined using an electron microscope. An electronic photograph is presented in figure 2. From a comparison of figures 1 and 2 it is seen that in the claimed enterosorbent fibers of the polysaccharide (lignin) are coated with fine-grained particles of boehmite. The X-ray phase composition of the sample of the obtained enterosorbent was studied on a DRON-2 device using R radiation of copper with a wavelength of 1.54178 and a nickel beta filter. The diffractometric characteristics of the sample are given in Table 1, from which it follows that the sample contains boehmite as the crystalline phase. Impurities of other crystalline phases were not found.

Table 1 Diffraction line number The experimental value of interplanar distances d _exp. , Å Reference value of interplanar distances d _ref. , (ASTM # 21-1307) Å for AlOOH (boehmite) one 6.1 6.11 2 3,167 3,164 3 2,348 2,346 four 1.98 1,983 5 1,865 1.86 6 1,847 1.85

Enterosorbent was similarly prepared using microcrystalline cellulose (Cellulose microcrystalline, powder, register, Chem. Abstr. 9004-34-6) or chitosan (Chitosan, from crab shells, register, Chem. Abstr. 9012-) as a polysaccharide. 76-4).

Tests of enterosorbent samples for adsorption capacity with respect to heavy metal ions Cd ²⁺ , Cu ²⁺ , CrO ₄ ^2- were carried out as follows. A portion of 0.10 g of enterosorbent containing polysaccharide and boehmite was poured with 10 ml of bidistilled water. Then, a solution of hydrochloric acid was added dropwise to pH = 5.5, after which a solution of a metal salt was introduced into the resulting solution to a concentration of 10 mg / L (10 PPM). The solution was stirred with a glass rod and left for 4 hours. Then it was filtered through a blue ribbon filter and heavy metals were determined by inversion voltammetry. Cations were determined on a mercury film electrode with a silver substrate. The chromate anion was determined on a working graphite electrode. The reference electrode is chlorine-silver in 1 M KCl. The electrochemical cell is a 15 ml quartz glass. The removal of dissolved oxygen was carried out by UV radiation of a mercury quartz lamp built into the analyzer, according to the method proposed in the work [E.A. Zakharova, G.M. Mokrousov, V.N. Volkova, V.N. Lisetskiy // Journal analyte. chemistry. - 1983.- t. 38, issue 9. - p. 1584-1586], against the background of 0.5 M formic acid. Voltammetric curves were recorded on a STA-1 analyzer (manufactured by ITM, Tomsk, RF) combined with a computer. The ion concentration was estimated by the additive method.

Data on the sorption ability of the samples of the inventive enterosorbent containing polysaccharide and boehmite, as well as analog and prototype are given in table.2.

table 2 Sample No. Characteristic % sorption of heavy metal ions Cd ²⁺ Cu ²⁺ CrO ₄ ^2- one Lignin + boehmite 83.0 99.92 95.0 2 Chitosan + boehmite 94.6 one hundred one hundred 3 MCC + boehmite 75.0 85.0 one hundred four Analogue 52.0 60.0 32,0 5 Prototype 42.0 71.5 88.0

In the samples of the declared enterosorbent, the ratio of the components was as follows: in the first sample, the lignin content was 60%, boehmite - 40%; in the second sample, the content of chitosan is 60%, boehmite - 40%; in the third sample, the MCC content is 45%, and boehmite is 55%.

To determine the optimal ratio of boehmite and polysaccharide, enterosorbent samples were prepared containing chitosan and boehmite at different component ratios, and the percentage of sorption of heavy metal ions Cd ²⁺ , Cu ²⁺ , CrO ₄ ^{2- was} determined. Data on the sorption ability of these samples are given in table 3.

Table 3 Sample No. The content of chitosan, wt.% The content of boehmite, wt.% % sorption of heavy metal ions Cd ²⁺ Cu ²⁺ CrO ₄ ^2- one 90 10 90.2 one hundred 88.0 2 80 twenty 94.0 one hundred 96.0 3 60 40 94.6 one hundred one hundred four 45 55 94.0 one hundred 96.4 5 35 65 87.0 one hundred 93.0

As can be seen from Table 3, enterosorbent containing chitosan and boehmite with the ratio of components: chitosan - 45-80%, boehmite - 55-20% has the best sorption characteristics with respect to heavy metal ions. When the content of boehmite in the enterosorbent is less than 20% and more than 55%, sorption properties deteriorate.

Similar percentage results were obtained when using lignin or MCC as a polysaccharide.

After numerous tests for the proposed enterosorbent, chitosan and lignin were selected as polysaccharides as providing the best sorption characteristics, and MCC as a relatively cheap and widespread substance.

As can be seen from tables 2 and 3, the inventive enterosorbent better absorbs heavy metal ions compared with the prototype: cations by 13-30%, anions - by 7-12%.

It should be noted that the claimed substance meets the requirements for enterosorbents, which are described, for example, in the work (Enterosorption / Edited by N.A. Belyakov. - L., 1991. - 336 p.).

We have also obtained positive results on the absorption of the claimed enterosorbent from the blood serum of such toxic substances as unconjugated bilirubin and creatinine.

Claims (2)

1. Enterosorbent for removing heavy metals containing a polysaccharide, characterized in that it additionally contains boehmite in the following ratio of components, wt.%: Polysaccharide 45-80 Boehmite Rest 2. Enterosorbent according to claim 1, characterized in that as a polysaccharide it contains chitosan, or lignin, or microcrystalline cellulose.

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