Quality detection method of pearl powder

Abstract

The invention discloses a quality detection method of pearl powder. The method at least comprises the following five-dimension detection: (1) detecting whether a sample to be detected contains starch; (2) detecting the content of acid-insoluble ash in the sample to be detected, and comparing the detection result with a threshold value; (3) detecting the content of heavy metal elements in the to-be-detected sample, and comparing a detection result with a threshold value; (4) detecting the total nitrogen content of the sample to be detected, and comparing the detection result with a threshold value; and (5) detecting the calcium content of the to-be-detected sample, and comparing the detection result with a threshold value. According to the method, the to-be-detected sample doped with starch can be eliminated, the to-be-detected sample with unqualified acid-insoluble ash content, heavy metal elements, total nitrogen content and calcium content can be eliminated, and primary inspection of the quality of the pearl powder sample is realized; the five-dimension inspection cost is relatively low, no excessive dependence on equipment is caused, and the audience is wide; after the five dimensions are integrated, the detection of the quality of the pearl powder is more systematic and accurate.

Description

Technical Field

[0001] The invention belongs to the technical field of pearl powder quality detection, and in particular relates to a pearl powder quality detection method. Summary of the invention

[0002] The invention aims to provide a method for detecting the quality of pearl powder.

[0003] A pearl powder quality testing method includes at least the following five dimensions of testing:

[0004] (1) Detecting whether the sample to be tested contains starch;

[0005] (2) detecting the content of acid-insoluble ash in the sample to be tested, and comparing the test result with a threshold value;

[0006] (3) detecting the content of heavy metal elements in the sample to be tested and comparing the test result with the threshold value;

[0007] (4) detecting the total nitrogen content of the sample to be tested, and comparing the test result with a threshold value;

[0008] (5) Detecting the calcium content of the sample to be tested and comparing the test result with the threshold value.

[0009] Preferably, in the above-mentioned quality detection method, in dimension (1), the sample to be tested is added to 10 times of water, boiled and then cooled, 1 drop of iodine solution is added, and the color of the solution is observed.

[0010] Preferably, in the above-mentioned quality detection method, in dimension (2), after the sample to be tested is incinerated until it is completely ashed, 10 times dilute hydrochloric acid is added to detect the content of acid-insoluble ash.

[0011] Preferably, in the above-mentioned quality detection method, in dimension (3), the heavy metal elements include at least one of lead, cadmium, arsenic, mercury and copper.

[0012] Preferably, in the above-mentioned quality detection method, in dimension (4), the sample to be tested is washed with water, and after drying, the total nitrogen content is detected by nitrogen determination method.

[0013] Preferably, in the above-mentioned quality inspection method, 50-60° warm water is used for cleaning.

[0014] Preferably, in the above-mentioned quality detection method, in dimension (5), the sample to be tested is first dissolved in acid, and then the pH of the solution is adjusted to 12.0 with a strong base, and finally titrated with EDTA standard solution to measure the calcium content.

[0015] Preferably, the above-mentioned quality detection method further comprises performing preliminary identification on the sample to be tested, and the preliminary identification comprises shape identification.

[0016] As further preferred, the preliminary identification also includes component identification, which is performed by at least one of the following methods:

[0017] ① Take 0.5g of the sample to be tested, put it in a mortar and add 3ml of water, grind it and transfer it to a test tube, add 10 drops of 10-100μM sodium hydroxide solution, shake well, then add 10 drops of 10-100μM copper sulfate solution drop by drop, shake well while adding, let it stand for 5-15min and observe the color of the upper liquid;

[0018] ②Take the sample to be tested and observe its color under ultraviolet light;

[0019] ③Take the sample to be tested, add dilute hydrochloric acid, and observe whether bubbles are generated; if bubbles are generated, filter the filtrate, add ammonium oxalate test solution, take the white precipitate produced by the reaction, add dilute hydrochloric acid and acetic acid respectively to observe its solubility. DETAILED DESCRIPTION

[0020] Specific implementation modes are listed below to further describe the technical solution of the present invention in detail.

[0021] Example 1

[0022] The present embodiment provides a method for detecting the quality of pearl powder, comprising the following steps:

[0023] 1. Preliminary identification

[0024] (1) Shape identification;

[0025] (2) Component identification, which is carried out in the following three ways:

[0026] ① Take 0.5g of the sample to be tested, put it in a mortar and add 3ml of water, grind it and transfer it to a test tube, add 10 drops of 10-100μM sodium hydroxide solution, shake well, then add 10 drops of 10-100μM copper sulfate solution drop by drop, shake well while adding, let it stand for 5-15min and observe the color of the upper liquid;

[0027] ②Take the sample to be tested and observe its color under ultraviolet light;

[0028] ③Take the sample to be tested, add dilute hydrochloric acid, and observe whether bubbles are generated; if bubbles are generated, filter the filtrate, add ammonium oxalate test solution, take the white precipitate produced by the reaction, add dilute hydrochloric acid and acetic acid respectively to observe its solubility.

[0029] 2. Quality Inspection

[0030] Quality inspection includes the following five dimensions of inspection:

[0031] (1) Detecting whether the sample to be tested contains starch;

[0032] Specifically, add the sample to be tested into 10 times water, boil it, let it cool, add 1 drop of iodine solution, and observe the color of the solution;

[0033] (2) detecting the content of acid-insoluble ash in the sample to be tested, and comparing the test result with a threshold value;

[0034] Specifically, after the sample to be tested is burned to complete ashing, 10 times dilute hydrochloric acid is added to detect the content of acid-insoluble ash;

[0035] (3) detecting the content of heavy metal elements in the sample to be tested and comparing the test result with the threshold value;

[0036] The heavy metal elements include at least one of lead, cadmium, arsenic, mercury and copper;

[0037] (4) detecting the total nitrogen content of the sample to be tested, and comparing the test result with a threshold value;

[0038] Specifically, the sample to be tested is washed with warm water at 60°C, and after drying, the total nitrogen content is detected by nitrogen determination method; the total nitrogen content threshold value set in this embodiment is 0.30-0.45%, and if it exceeds the threshold range, the quality of the sample to be tested is determined to be unqualified;

[0039] (5) detecting the calcium content of the sample to be tested, and comparing the test result with a threshold value;

[0040] Specifically, the sample to be tested is first dissolved in dilute hydrochloric acid, and then the pH of the solution is adjusted to 12.0 with sodium hydroxide, and finally titrated with EDTA standard solution to measure the calcium content;

[0041] The calcium content threshold value set in this embodiment is 30-40%. If the calcium content exceeds the threshold value range, the sample to be tested is judged to be unqualified.

[0042] When quality inspection is performed from five dimensions, the more dimensions that pass, the higher the quality level of the sample to be tested.

Claims

1. A method for detecting the quality of pearl powder, characterized in that: At least the following five dimensions are included: (1) Detecting whether the sample to be tested contains starch; (2) detecting the content of acid-insoluble ash in the sample to be tested, and comparing the test result with a threshold value; (3) detecting the content of heavy metal elements in the sample to be tested and comparing the test result with the threshold value; (4) detecting the total nitrogen content of the sample to be tested, and comparing the test result with a threshold value; (5) Detecting the calcium content of the sample to be tested and comparing the test result with the threshold value.

2. The quality inspection method according to claim 1, characterized in that: In dimension (1), add the sample to be tested into 10 times the amount of water, boil it, let it cool, add 1 drop of iodine solution, and observe the color of the solution.

3. The quality inspection method according to claim 1, characterized in that: In dimension (2), after the sample to be tested is calcined until it is completely ashed, 10 times dilute hydrochloric acid is added to detect the content of acid-insoluble ash.

4. The quality inspection method according to claim 1, characterized in that: In dimension (3), the heavy metal elements include at least one of lead, cadmium, arsenic, mercury and copper.

5. The quality inspection method according to claim 1, characterized in that: In dimension (4), the sample to be tested is washed with water, dried, and then the total nitrogen content is detected by nitrogen determination method.

6. The quality inspection method according to claim 5, characterized in that: Wash with warm water at 50-60°.

7. The quality inspection method according to claim 1, characterized in that: In dimension (5), the sample to be tested is first dissolved in acid, and then the pH of the solution is adjusted to 12.0 with a strong base, and finally titrated with EDTA standard solution to measure the calcium content.

8. The quality inspection method according to claim 1, characterized in that: The method also includes performing preliminary identification on the sample to be tested, wherein the preliminary identification includes shape identification.

9. The quality inspection method according to claim 8, characterized in that: The preliminary identification also includes component identification, which is performed by at least one of the following methods: ① Take 0.5g of the sample to be tested, put it in a mortar and add 3ml of water, grind it and transfer it to a test tube, add 10 drops of 10-100μM sodium hydroxide solution, shake well, then add 10 drops of 10-100μM copper sulfate solution drop by drop, shake well while adding, let it stand for 5-15min and observe the color of the upper liquid; ②Take the sample to be tested and observe its color under ultraviolet light; ③Take the sample to be tested, add dilute hydrochloric acid, and observe whether bubbles are generated; if bubbles are generated, filter the filtrate, add ammonium oxalate test solution, take the white precipitate produced by the reaction, add dilute hydrochloric acid and acetic acid respectively to observe its solubility.