阅读说明：本技术 一种去除西瓜霜中重金属离子的方法 (Method for removing heavy metal ions in watermelon frost ) 是由 潘玉杰 覃广源 黄磁钢 闫贇 孙田甜 陈华容 吴玉春 冉娜 孙梁琨 于 2020-05-22 设计创作，主要内容包括：本发明公开了一种去除西瓜霜中重金属离子的方法,包括以下步骤：a、西瓜霜溶解：取适量西瓜霜,加水溶解,得西瓜霜溶液,即A品；b、活性炭吸附：取适量活性炭,加入A品中对重金属离子进行吸附,搅拌,过滤,得西瓜霜滤液,即B品；c、重结晶：向B品中加入适量乙醇,搅拌均匀,静置析晶,过滤,得西瓜霜结晶,即C品；d、烘干：将C品于适宜温度下烘干,得西瓜霜精制品。本发明可有效解决西瓜霜粗制品中重金属含量超标的问题,拓宽了重金属含量超标的西瓜霜的应用,提高了重金属含量超标的西瓜霜的利用价值,并且本发明中西瓜霜的收率高。(The invention discloses a method for removing heavy metal ions in watermelon frost, which comprises the following steps: a. dissolving watermelon frost: dissolving appropriate amount of watermelon crystal in water to obtain watermelon crystal solution A; b. activated carbon adsorption: adding appropriate amount of activated carbon into product A, adsorbing heavy metal ions, stirring, and filtering to obtain watermelon crystal filtrate, i.e. product B; c. and (3) recrystallization: adding appropriate amount of ethanol into product B, stirring, standing for crystallization, and filtering to obtain watermelon crystal, product C; d. drying: and drying the product C at a proper temperature to obtain a refined watermelon frost product. The invention can effectively solve the problem that the content of heavy metal in the watermelon frost crude product exceeds the standard, broadens the application of the watermelon frost with the content of heavy metal exceeding the standard, improves the utilization value of the watermelon frost with the content of heavy metal exceeding the standard, and has high yield of the watermelon frost.)

1. A method for removing heavy metal ions in watermelon frost is characterized by comprising the following steps: the method comprises the following steps:

a. dissolving watermelon frost: dissolving appropriate amount of watermelon crystal in water to obtain watermelon crystal solution A;

b. activated carbon adsorption: adding appropriate amount of activated carbon into product A, adsorbing heavy metal ions, stirring, and filtering to obtain watermelon crystal filtrate, i.e. product B;

c. and (3) recrystallization: adding appropriate amount of ethanol into product B, stirring, standing for crystallization, and filtering to obtain watermelon crystal, product C;

d. drying: and drying the product C at a proper temperature to obtain a refined watermelon frost product.

2. The method for removing heavy metal ions in watermelon frost according to claim 1, wherein the method comprises the following steps: in the step a, the dissolving temperature is 40-50 ℃, and the concentration of the watermelon frost solution is 0.025-0.1 g/mL.

3. The method for removing heavy metal ions in watermelon frost according to claim 2, wherein the method comprises the following steps: in the step a, the dissolving temperature is 40-45 ℃, and the concentration of the watermelon frost solution is 0.03-0.06 g/mL.

4. The method for removing heavy metal ions in watermelon frost according to claim 3, wherein the method comprises the following steps: in the step a, the dissolving temperature is 40 ℃, and the concentration of the watermelon frost solution is 0.04 g/mL.

5. The method for removing heavy metal ions in watermelon frost according to claim 1, wherein the method comprises the following steps: in the step b, the weight ratio of the watermelon frost to the active carbon is 1 (8-15), the adsorption temperature is 45-55 ℃, and the stirring time is 3-6 h.

6. The method for removing heavy metal ions in watermelon frost according to claim 5, wherein the method comprises the following steps: in the step b, the weight ratio of the watermelon frost to the active carbon is 1:10, the adsorption temperature is 50 ℃, and the stirring time is 3 hours.

7. The method for removing heavy metal ions in watermelon frost according to claim 5, wherein the method comprises the following steps: and in the step b, still standing is further included after stirring, and the still standing time is 8-16 h.

8. The method for removing heavy metal ions in watermelon frost according to claim 1, wherein the method comprises the following steps: in the step c, the mass ratio of the watermelon frost to the ethanol is 1 (10-30), the standing temperature is 1-5 ℃, and the standing time is 24-72 hours.

9. The method for removing heavy metal ions in watermelon frost according to claim 4, wherein the method comprises the following steps: in the step c, the volume ratio of the watermelon frost filtrate to the ethanol is 1 (1-2.8), the standing temperature is 1-5 ℃, and the standing time is 24-72 hours.

10. The method for removing heavy metal ions in watermelon frost according to claim 9, wherein the method comprises the following steps: in the step c, the volume ratio of the watermelon frost filtrate to the ethanol is 1:2, the standing temperature is 2 ℃, and the standing time is 48 hours.

Technical Field

The invention relates to the technical field of watermelon frost refining, in particular to a method for removing heavy metal ions in watermelon frost.

Background

The watermelon crystal is collected in the part of '2020 edition of Chinese pharmacopoeia', is prepared from mature fresh fruits of Cucurbitaceae watermelon Citrullus lanatus (Thunb.) Matsumu.et Nakai and Mirabilitum, has heavy metal content of not more than 10mg/kg, and is commonly used for treating stomatitis, oral ulcer, acute and chronic pharyngolaryngitis, tonsillitis, otitis media, etc. The processing method of the watermelon frost recorded in the prior teaching material of traditional Chinese medicine processing comprises the following steps: taking fresh ripe watermelon, cutting a thick sheet at one end of the watermelon pedicle to be used as a top cover, digging out the pulp, filling mirabilite into the watermelon, covering the top cover, firmly sticking the watermelon by using a bamboo stick, supporting the watermelon by using a bowl or a disc, hanging the watermelon in a ventilated and cool place, scraping the watermelon at any time when white frost is separated out from the surface of the watermelon until no white frost is separated out, and airing the watermelon. Or cutting fresh watermelon into pieces, placing the pieces into a pottery jar without glaze, sealing the jar opening, hanging in a shady and ventilated place, separating white crystal out of the pottery jar after several days, and collecting the white crystal after separation until no crystal is separated out.

After the processes of the investigation and the research,the heavy metal content of watermelon frost purchased in the market is found to exceed the content specified in Chinese pharmacopoeia frequently. By analyzing the processing process, two possibilities are provided for introducing heavy metals and causing the content of the heavy metals to exceed the standard: 1. introducing heavy metals into water and soil of the watermelon production place; 2. the Natrii sulfas used in the processing process contains heavy metals, is a sulfate mineral, and is processed and refined to obtain crystal with Na as main ingredient₂SO₄。

At present, the processing process of the watermelon frost can not effectively remove heavy metal ions in the watermelon frost, thereby limiting the use of the watermelon frost with excessive heavy metal content, reducing the utilization value of the watermelon frost and causing medicine waste. Therefore, how to effectively solve the problem that the heavy metal ions in the watermelon frost exceed the standard, widen the application of the watermelon frost with the heavy metal content exceeding the standard, improve the utilization value of the watermelon frost and solve the problem of medicine waste is particularly urgent.

Disclosure of Invention

The invention aims to provide a method for removing heavy metal ions in watermelon frost. The invention can effectively solve the problem that the content of heavy metal in the watermelon frost crude product exceeds the standard, broadens the application of the watermelon frost with the content of heavy metal exceeding the standard, improves the utilization value of the watermelon frost, solves the problem of medicine waste, and has high yield of the watermelon frost.

The technical scheme of the invention is as follows: a method for removing heavy metal ions in watermelon frost comprises the following steps:

a. dissolving watermelon frost: dissolving appropriate amount of watermelon crystal in water to obtain watermelon crystal solution A;

b. activated carbon adsorption: adding appropriate amount of activated carbon into product A, adsorbing heavy metal ions, stirring, and filtering to obtain watermelon crystal filtrate, i.e. product B;

c. and (3) recrystallization: adding appropriate amount of ethanol into product B, stirring, standing for crystallization, and filtering to obtain watermelon crystal, product C;

d. drying: and drying the product C at a proper temperature to obtain a refined watermelon frost product.

In the foregoing method for removing heavy metal ions from watermelon frost, in step a, the water is purified water.

In the method for removing heavy metal ions in watermelon frost, in step a, the dissolving temperature is 40-50 ℃, and the concentration of the watermelon frost solution is 0.025-0.1 g/mL.

In the method for removing heavy metal ions in watermelon frost, in step a, the dissolving temperature is 40-45 ℃, and the concentration of the watermelon frost solution is 0.03-0.06 g/mL.

In the method for removing heavy metal ions in watermelon frost, in step a, the dissolving temperature is 40 ℃, and the concentration of the watermelon frost solution is 0.04 g/mL.

In the method for removing the heavy metal ions in the watermelon frost, in the step b, the weight ratio of the watermelon frost to the active carbon is 1 (8-15), the adsorption temperature is 45-55 ℃, and the stirring time is 3-6 h.

In the method for removing heavy metal ions in watermelon frost, in the step b, the weight ratio of the watermelon frost to the active carbon is 1:10, the adsorption temperature is 50 ℃, and the stirring time is 3 hours.

In the method for removing heavy metal ions in watermelon frost, in step b, still standing is further included after stirring, and the standing time is 8-16 h.

In the method for removing the heavy metal ions in the watermelon frost, in the step c, the mass ratio of the watermelon frost to the ethanol is 1 (10-30), the standing temperature is 1-5 ℃, and the standing time is 24-72 hours.

In the method for removing the heavy metal ions in the watermelon frost, in the step c, the volume ratio of the watermelon frost filtrate to the ethanol is 1 (1-2.8), the standing temperature is 1-5 ℃, and the standing time is 24-72 hours.

In the method for removing heavy metal ions in watermelon frost, in step c, the volume ratio of the watermelon frost filtrate to ethanol is 1:2, the standing temperature is 2 ℃, and the standing time is 48 hours.

In the method for removing heavy metal ions in watermelon crystal, in step c, the ethanol is an ethanol solution with a mass fraction of 95%.

In the method for removing heavy metal ions in watermelon frost, in the step d, the drying temperature is 40-60 ℃. The drying temperature is moderate, and the energy consumption can be reduced.

Compared with the prior art, the method has the advantages that the watermelon frost is prepared into proper concentration, proper amount of active carbon is added for adsorption, the adsorption condition is controlled, and the watermelon frost filtrate after heavy metal ions are adsorbed is recrystallized in the presence of proper amount of ethanol. The invention can effectively remove heavy metal ions in the watermelon frost, the content of heavy metal in the prepared finished product meets the requirements of Chinese pharmacopoeia, and the yield of the watermelon frost can reach more than 90 percent. The method for crystallizing the watermelon frost filtrate by using the ethanol can further improve the removal rate of heavy metals. The activated carbon can adsorb and decolor natural pigment introduced in the processing process of the watermelon frost, and effectively solves the problem of false positive when the heavy metal content of the watermelon frost is detected according to the standard of Chinese pharmacopoeia. The invention provides an effective solution for the problem of excessive heavy metal content of watermelon frost in the market for the first time, can ensure that the heavy metal content in the treated watermelon frost meets the requirements of Chinese pharmacopoeia, can broaden the application of the watermelon frost with excessive heavy metal content, improves the utilization value of the watermelon frost, and solves the problem of medicine waste. The invention can effectively improve the quality of the watermelon frost decoction pieces, has simple method and high yield of the watermelon frost, and is easy for industrialized application. The invention can effectively solve the problem that the content of heavy metal in the watermelon frost crude product exceeds the standard, broadens the application of the watermelon frost with the content of heavy metal exceeding the standard, improves the utilization value of the watermelon frost with the content of heavy metal exceeding the standard, solves the problem of medicine waste, and has high yield of the watermelon frost.

Drawings

FIG. 1 is a schematic flow chart of the present invention.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.