CN105510327A - Method for identifying traditional Chinese medicine material sulfur residues - Google Patents

Abstract

The invention discloses an identification method for sulfur residues in Chinese medicinal materials, which belongs to the field of analysis and detection of chemical substance residues, and comprises the following steps: pulverizing Chinese medicinal materials and putting them into a flask; adding distilled water and performing ultrasonic treatment; adding hydrochloric acid solution; heating and distilling; The fractions were taken up with strong alkaline solution. Add oxidant to the absorbing liquid and heat. Finally, add the absorption liquid dropwise into a precipitant solution such as barium nitrate, observe whether there is precipitation, and identify whether the Chinese medicinal materials contain sulfur residues. The detection limit of this method reaches 1 μg/g. The invention can quickly and effectively identify sulfur residues in various Chinese medicinal materials, has universal applicability, is low in cost, simple in operation and easy to popularize.

Description

Identification method of sulfur residues in traditional Chinese medicinal materials

technical field

The invention relates to an identification method for sulfur residues in Chinese medicinal materials, in particular to an oxidation treatment and precipitation identification method for sulfur residues in samples.

Background technique

Sulfur fumigation is a treatment technology for Chinese medicinal materials developed since the 1960s. Sulfur dioxide produced during sulfur fumigation can accelerate the drying of Chinese herbal medicines, prevent mold and deterioration of Chinese herbal medicines, and increase the color and beauty of Chinese herbal medicines. Therefore, it is widely used in the processing of various Chinese herbal medicines. At present, Chinese medicinal materials that are fumigated with sulfur include: ginseng, Codonopsis pilosula, American ginseng, Angelica dahurica, yam, lily, wolfberry, astragalus, chrysanthemum, honeysuckle, tremella and more than 20 commonly used Chinese medicinal materials. However, a large number of research results have shown that sulfur fumigation will cause deterioration of the taste of Chinese medicinal materials, loss of biologically active components, and residues of sulfites and heavy metals. After being used as medicine, it will not only lead to a decrease in the efficacy of the medicine, but also cause harm to the body of the eater. Therefore, the 2005 edition of the Chinese Pharmacopoeia deleted the content of using sulfur to fumigate Chinese herbal medicines, and included the sulfur dioxide residual determination method in the 2010 edition of the Chinese Pharmacopoeia. In the Pharmacopoeia, the powder of traditional Chinese medicinal materials is subjected to acid hydrolysis and distillation, the overflowing sulfur dioxide is absorbed with starch aqueous solution, and the residual sulfur dioxide is calibrated with iodine solution.

The detection methods of sulfur dioxide in Chinese medicinal materials include rapid qualitative identification and quantitative determination. Rapid qualitative identification is a method to realize the qualitative identification of sulfur dioxide by using the relevant physical and chemical properties of sulfur dioxide or simple instruments. It has the advantages of low cost, simple and intuitive, and is suitable for the identification of batch samples. At present, the rapid identification methods of sulfur dioxide include pH identification method, Fourier transform infrared spectroscopy, improved ancient Chua's method, iodine test solution method and barium chloride precipitation method (Xie Yunlong, Lei Peng, Chinese Journal of Modern Medicine, 2001, 11( 7):95, 98; Liu Jingjing, Liu Xiao, Li Songlin, etc., Journal of Nanjing University of Traditional Chinese Medicine, 2010, 26(5):356-358; Hao Yanjun, Xu Qiuyang, Sang Yuli, etc., Chinese Journal of Traditional Chinese Medicine, 2012, 37(3 ):335-337; Yang Dequan, Yuan Hong, Herald of Traditional Chinese Medicine, 2009, 15(9):51-52), the types of identification methods are relatively few, and lack of broad-spectrum data support.

Contents of the invention

The technical problem to be solved by the present invention is to provide a rapid identification method applicable to sulfur residues of various Chinese medicinal materials treated by sulfur fumigation. The identification method is accurate, intuitive, simple and easy to implement, and the cost is very low.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A method for identifying sulfur residues in Chinese medicinal materials, comprising the following steps:

Step 1 Sample solution: Take Chinese herbal medicines and crush them into fine powder; accurately weigh 2-10g of Chinese herbal medicines fine powder and put them into a flask, add distilled water, and ultrasonically treat for 5-15 minutes; then add hydrochloric acid solution into the bottle; connect the flask On the distillation device, heat and distill, and absorb the fraction with a strong alkali solution; after the distillation is completed, adjust the pH value of the fraction solution to 6.0-8.0 to obtain solution a;

Step 2 Sample oxidation: add an oxidizing agent to solution a, heat for 8-12 minutes, and then concentrate to obtain solution b;

Step 3 Sample identification: Add solution b to the precipitant solution. If precipitation is observed, the sample contains residual sulfur dioxide, and the residual amount is greater than or equal to 1 μg/g; otherwise, the residual sulfur dioxide in the sample is less than 1 μg/g.

The further improvement of the present invention is that: the particle size of the fine powder in step 1 is less than 1 mm.

The further improvement of the present invention is: in step 1, the volume of distilled water is 150mL, the distillation temperature is 90-110°C, the ultrasonic treatment time is 10 minutes, the volume concentration of the hydrochloric acid solution used is 1:1, and the consumption of the hydrochloric acid solution is 50mL, The strong alkali solution is sodium hydroxide solution or potassium hydroxide solution, the concentration of the strong alkali solution is 0.05-0.2mol/L, and the volume of the distilled fraction solution is 50-70mL.

The further improvement of the present invention is that: the oxidant in step 2 is hydrogen peroxide or ozone, the heating reaction time is 10 minutes, and the volume of solution b concentrated in step 2 is 10 mL.

The further improvement of the present invention is that: the precipitating agent in step three is water-soluble calcium salt, lead salt or barium salt; the concentration of the precipitating agent solution is 0.1-10 mmol/L, and the amount of the precipitating agent solution is not more than 10 mL.

The further improvement of the present invention lies in that the precipitation agent is any one of calcium nitrate, lead nitrate, barium nitrate, calcium chloride or barium chloride.

The further improvement of the present invention is that: the amount of fine powder of Chinese medicinal materials in step 1 is 5g; the distillation temperature is 100°C; the strong alkali solution has a concentration of 0.1mol/L sodium hydroxide solution or potassium hydroxide solution; the distilled liquid volume 60mL; in step 2, the oxidizing agent is hydrogen peroxide; in step 3, the precipitant is barium chloride.

The further improvement of the present invention is that: the Chinese medicinal material is one or a combination of two or more of ginseng, Codonopsis pilosula, American ginseng, Angelica dahurica, yam, lily, wolfberry, astragalus, chrysanthemum, honeysuckle and white fungus.

Owing to having adopted above-mentioned technical scheme, the technical progress that the present invention obtains is:

In the sample solution step of the method of the present invention, the acidification treatment of the Chinese medicinal materials refers to methods known in the art (for example, the appendix of the Chinese Pharmacopoeia 2010 edition) to release the residual sulfur dioxide in the Chinese medicinal materials. The difference from the Chinese Pharmacopoeia is that firstly, the fine powder of Chinese medicinal materials is cleaned with ultrasonic waves in an aqueous solution, which is beneficial to the infiltration of the fine powder of Chinese medicinal materials by distilled water. Then, heating under acidic conditions facilitates the overflow of sulfur dioxide from the solution. In the present invention, the solution is heated to boiling. On the one hand, the solubility of sulfur dioxide in water is lower at a higher temperature; on the other hand, water vapor can carry the sulfur dioxide to overflow from the solution. The overflowing sulfur dioxide reacts with strong alkali to generate sulfite, so the sulfur element in the solution a obtained by this method exists in the form of sulfite, that is, the residual sulfur in Chinese medicinal materials will be converted into sulfite, the main chemical The response is:

SO ₂ +NaOH→Na ₂ SO ₃

The invention controls the pH value of the solution a within a certain range, which can prevent the precipitant solution from generating hydroxide precipitates under alkaline conditions, thereby interfering with the identification results.

In the step of sample oxidation, the generated sodium sulfite has certain reducibility, and the present invention converts sulfite into sulfate by adding an oxidizing agent to the solution, and the main chemical reaction is:

SO ₃ ^2- +H ₂ O ₂ →SO ₄ ^2- +H ₂ O

Appropriately shrinking the distillate solution in the present invention is an important step for successful identification. By concentrating the solution, the concentration of sulfate ions in the solution becomes larger, and it is easier to react with the precipitant to form a precipitate, which is beneficial to the identification of low-residue Chinese herbal medicine samples.

In the step of sample identification, by adding a certain volume of solution b dropwise to the precipitant solution, the sulfate ions converted from sulfur dioxide will react with the precipitant to form a precipitate visible to the naked eye, thereby achieving the purpose of rapid identification of sulfur dioxide. The main chemical The response is:

SO ₄ ^2- +Pb ²⁺ →PbSO ₄ ↓

SO ₄ ^2- +Ca ²⁺ →CaSO ₄ ↓

SO ₄ ^2- +Ba ²⁺ →BaSO ₄ ↓

Since the solubility product of barium sulfate (K _sp =1.1×10 ^-11 ) is very small, when the concentration of sulfate is very low, it can still react with barium salt to form a precipitate. Therefore, this identification method can effectively identify sulfur dioxide residues in Chinese herbal medicines. After properly adjusting the concentration of the precipitant solution, the detection limit of the method can reach 1 μg/g, that is, a certain volume of solution b is added dropwise to a certain concentration of the precipitant solution. If precipitation is observed, the sample contains residual sulfur dioxide. , the residual amount is greater than or equal to 1 μg/g; otherwise, the residual amount of sulfur dioxide in the sample is less than 1 μg/g. Therefore, the method of the present invention is suitable for the quality detection of Chinese medicinal materials with high requirements (the Chinese Pharmacopoeia's general rules for the verification of medicinal materials and decoction pieces stipulate that the residual amount of sulfur dioxide in Chinese medicinal materials and decoction pieces shall not exceed 150 μg/g).

The method of the invention has a lower detection limit, and the amount of traditional Chinese medicinal materials required for detection is less. The method of the invention can detect residual sulfur in more than ten kinds of Chinese medicinal materials such as ginseng, codonopsis, American ginseng, angelica, yam, lily, wolfberry, astragalus, chrysanthemum, honeysuckle, white fungus, etc., and has a wide range of applications. The method of the invention is convenient to combine, does not pollute the environment, and has better environmental protection. In addition to being used for the identification of sulfur residues in Chinese medicinal materials, the method of the present invention can also be used in some dried fruits, in which pyrosulfite is often added as a preservative, and pyrosulfite in the present invention also has a high degree of sensitivity , can realize the detection of pyrosulfite.

Description of drawings

Fig. 1 is the flowchart of the embodiment of the present invention;

Figure 2 is a photo of the detection results of different sulfur residue yam samples detected by the method of the present invention.

detailed description

A method for identifying sulfur residues in traditional Chinese medicinal materials, the applicable Chinese medicinal materials are one or a combination of two or more of ginseng, Codonopsis pilosula, American ginseng, angelica dahurica, yam, lily, wolfberry, astragalus, chrysanthemum, honeysuckle and tremella. Include the following steps:

Step 1 sample solution: take Chinese herbal medicines and grind them into fine powders, the particle size (particle diameter) of the fine powders is less than 1 mm. Accurately weigh 2-10g of fine powder of Chinese medicinal materials and put them into a flask, add 150mL of distilled water, and ultrasonically treat for 5-15 minutes, preferably 10 minutes; then add 50mL of 1:1 (volume concentration) hydrochloric acid solution into the bottle; Connect to the distillation device, heat distillation, the distillation temperature is 90-110°C, preferably 100°C, absorb the fraction with a strong alkali solution, the strong alkali solution is sodium hydroxide solution or potassium hydroxide solution, and the concentration of the strong alkali solution is 0.05 ~0.2mol/L; after the distillation, adjust the pH value of the distillate solution to 6.0~8.0, and the volume of the distilled liquid is 50~70mL to obtain solution a.

Step 2 Sample oxidation: add an oxidizing agent to the solution a, the oxidizing agent is hydrogen peroxide or ozone, preferably hydrogen peroxide; heat the reaction for 8 to 12 minutes, preferably 10 minutes, and then concentrate. The volume of the concentrated sample solution is 10 mL to obtain a solution b;

Step 3 Sample identification: add solution b to no more than 10mL of precipitant solution, the precipitant is water-soluble calcium salt, lead salt, barium salt; the concentration of precipitant solution is 0.1-1mmol/L, if observed When the precipitate is formed, the sample contains residual sulfur dioxide, and the residual amount is greater than or equal to 1 μg/g; otherwise, the residual sulfur dioxide in the sample is less than 1 μg/g. The precipitation agent is preferably any one of calcium nitrate, lead nitrate, barium nitrate, calcium chloride, barium chloride.

Below in conjunction with embodiment the present invention is described in further detail:

The fresh samples of Chinese medicinal materials used in the following examples were all purchased from farmers' markets. The natural drying process of Chinese medicinal materials is to place the purchased Chinese medicinal materials in a dry and ventilated place, and turn them regularly until the quality of the Chinese medicinal materials does not change. The drying time is 10 days. The sulfur fumigation drying process of Chinese herbal medicines is to fumigate the purchased Chinese herbal medicines with sulfur for 2 hours, place them in a dry and ventilated place, and turn them regularly until the quality of Chinese herbal medicines does not change any more. The drying time is 5 days. Before identification, the samples of Chinese herbal medicines were pulverized, and the particle size of the fine powder was less than 1mm.

Example 1:

Accurately weigh 5g of sulfur-fumigation-dried and natural-dried yam fine powder, add them to two round-bottomed flasks respectively, and then use the same method below to identify the sulfur content in the two Chinese herbal medicines. Add 150 mL of distilled water and sonicate for 10 minutes. Then add 50 mL of 1:1 (volume concentration, the same below) hydrochloric acid solution into the bottle. Connect the round-bottomed flask to a distillation device, heat and distill, the distillation temperature is 100°C, the fraction is collected with 0.1mol/L sodium hydroxide solution, and the volume of the distilled liquid is 60mL. After the distillation, adjust the pH value of the distillate solution to about 7. Add hydrogen peroxide (volume concentration is 30%, the same below) into the solution and heat. The solution was concentrated to 10 mL, and the resulting solution was added dropwise to 5 ml of barium chloride solution with a concentration of 1 mmol/L. The generation of white precipitate was observed in the sample solution of sulfur-fumigated yam powder, and the identification result was that the sample contained residual sulfur dioxide, which was greater than 1 μg/g. The naturally dried yam powder sample was detected by the same method as above, and the naturally dried yam powder sample solution was very clear, and the identification result showed that there was no residual sulfur dioxide in the sample. After adopting other methods other than the present invention to verify, the result is the same as that of this embodiment.

Do not add or add quantitative sodium sulfite to the yam fine powder of natural drying, carry out experiment according to the method of the present invention, and experimental result is as shown in Figure 2. The corresponding solutions of the yam samples without adding sodium sulfite did not appear turbid, while the corresponding solutions of the samples added with different amounts of sodium sulfite clearly saw the formation of white precipitates, and the experimental results were clear and without interference.

Example 2:

Accurately weigh 2g of sulfur fumigation-dried and natural-dried white fungus fine powder, put them into two round-bottomed flasks respectively, and then use the following same method to identify the sulfur content in the two kinds of Chinese medicinal materials. Add 150 mL of distilled water and sonicate for 10 minutes. Then add 50 mL of 1:1 hydrochloric acid solution to the bottle. Connect the flask to a distillation device, heat and distill, and collect fractions with 0.05mol/L potassium hydroxide solution. After the distillation, adjust the pH value of the distillate solution to 6.5. Hydrogen peroxide (30%) was added to the solution and heated. The solution was concentrated to 10 mL, and the resulting solution was added dropwise to 5 ml of lead nitrate solution with a concentration of 1 mmol/L. The generation of white precipitate was observed in the sample solution of sulfur-fumigated tremella powder, and the identification result showed that the sample contained residual sulfur dioxide, and the residual amount was greater than 1 μg/g. The natural drying tremella powder sample solution is very clear, and the identification result shows that there is no residual sulfur dioxide in the sample. After adopting other methods other than the present invention to verify, the result is the same as that of this embodiment.

Example 3:

Accurately weigh 10g of sulfur fumigation-dried and natural-dried Astragalus fine powder, add them into two round-bottomed flasks respectively, and then use the following method to identify the sulfur content in the two kinds of Chinese herbal medicines. Add 150 mL of distilled water and sonicate for 10 minutes. Then add 50 mL of 1:1 hydrochloric acid solution to the bottle. Connect the round-bottomed flask to a distillation device, heat and distill, and collect the fractions with 0.2mol/L sodium hydroxide solution. After the distillation, adjust the pH value of the distillate solution to 8.0. Hydrogen peroxide (30%) was added to the solution and heated. The solution was concentrated to 10 mL, and the resulting solution was added dropwise to 5 ml of calcium nitrate solution with a concentration of 1 mmol/L. The formation of white precipitate was observed in the sulfur-fumigated Astragalus powder sample solution, and the identification result showed that the sample contained residual sulfur dioxide, and the residual amount was greater than 1 μg/g. The naturally dried Astragalus powder sample solution was very clear, and the identification result showed that there was no residual sulfur dioxide in the sample. After adopting other methods other than the present invention to verify, the result is the same as that of this embodiment.

Example 4:

Accurately weigh 5g of sulfur fumigation-dried and natural-dried Codonopsis pilosula fine powder, put them into two round-bottomed flasks respectively, and then use the following same method to identify the sulfur content in the two kinds of Chinese herbal medicines. Add 150 mL of distilled water and sonicate for 10 minutes. Then add 50 mL of 1:1 hydrochloric acid solution to the bottle. Connect the round-bottomed flask to a distillation device, heat and distill, and collect the fractions with 0.1mol/L sodium hydroxide solution. After the distillation, adjust the pH value of the distillate solution to 6.0. Hydrogen peroxide (30%) was added to the solution and heated. The solution was concentrated to 10 mL, and the resulting solution was added dropwise to 5 ml of barium nitrate solution with a concentration of 1 mmol/L. The generation of white precipitate was observed in the sample solution of Codonopsis pilosula powder smoked with sulfur, and the identification result showed that the sample contained sulfur dioxide residue, and the residue amount was greater than 1 μg/g. Naturally dried Codonopsis pilosula powder sample solution is very clear, and the identification result shows that there is no residual sulfur dioxide in the sample. After adopting other methods other than the present invention to verify, the result is the same as that of this embodiment.

Claims (8)

1. the authentication method that Chinese crude drug sulphur is residual, is characterized in that comprising the following steps:

Step one desampling: get Chinese crude drug, is ground into fine powder; Accurately take Chinese crude drug fine powder 2 ~ 10g and put into flask, add distilled water, ultrasound wave process 5 ~ 15 minutes; Then in bottle, hydrochloric acid solution is added; Flask is connected on distilling apparatus, adds thermal distillation, absorb cut with strong base solution; After distillation terminates, regulate cut solution ph to 6.0 ~ 8.0, obtain solution a;

Step 2 sample oxidation: add oxygenant in solution a, adds thermal response 8 ~ 12 minutes, then concentrates, obtain solution b;

Step 3 sample identification: be added dropwise to certain volume solution b in precipitant solution, generates if observe precipitation, then contain sulfur dioxide residue in sample, and residual quantity is more than or equal to 1 μ g/g; Otherwise then in sample, sulfur dioxide residual quantity is less than 1 μ g/g.

2. the authentication method that Chinese crude drug sulphur according to claim 1 is residual, is characterized in that: the granularity of fine powder described in step one is less than 1mm.

3. the authentication method that Chinese crude drug sulphur according to claim 1 is residual, it is characterized in that: in step one, the volume of distilled water is 150mL, vapo(u)rizing temperature is 90 ~ 110 DEG C, and ultrasonic treatment time is 10 minutes, and the volumetric concentration of used salt acid solution is 1:1, the consumption of hydrochloric acid solution is 50mL, strong base solution is sodium hydroxide solution or potassium hydroxide solution, and strong base solution concentration is 0.05 ~ 0.2mol/L, and the cut liquor capacity distilled out is 50 ~ 70mL.

4. the authentication method that Chinese crude drug sulphur according to claim 3 is residual, is characterized in that: oxygenant described in step 2 is hydrogen peroxide or ozone, and the heating reaction time is 10 minutes, and the solution b volume after concentrated in step 2 is 10mL.

5. the authentication method that Chinese crude drug sulphur according to claim 4 is residual, is characterized in that: precipitation agent described in step 3 is water miscible calcium salt, lead salt or barium salt; The concentration of precipitant solution is 0.1 ~ 10mmol/L, and the consumption of precipitant solution is not more than 10mL.

6. the authentication method that Chinese crude drug sulphur according to claim 5 is residual, is characterized in that: precipitation agent is any one in calcium nitrate, plumbi nitras, barium nitrate, lime chloride or barium chloride.

7. the authentication method that Chinese crude drug sulphur according to claim 5 is residual, is characterized in that: the Chinese crude drug fine powder amount in step one is 5g; Vapo(u)rizing temperature is 100 DEG C; Strong base solution is concentration is 0.1mol/L sodium hydroxide solution or potassium hydroxide solution; The liquid volume distilled out is 60mL; Oxygenant described in step 2 is hydrogen peroxide; Precipitation agent described in step 3 is barium chloride.

8. the authentication method that the Chinese crude drug sulphur according to claim 1 ~ 7 any one is residual, is characterized in that: described Chinese crude drug is one or more the combination in ginseng, Radix Codonopsis, American Ginseng, the root of Dahurain angelica, Chinese yam, lily, matrimony vine, the Radix Astragali, chrysanthemum, honeysuckle, white fungus.