A method for identifying talcum powder and talc

Abstract

The present invention discloses a method for identifying talcum powder and toilet powder, and the method comprises the following steps: S100. Obtain the standard slope k value or standard bar code of each standard product of the object to be measured according to the following steps, and judge the object to be measured according to the k value or bar code; the object to be measured is talcum powder or toilet powder. The present invention provides a method for detecting and identifying talcum powder and toilet powder by a catalytic luminescence sensor. According to the catalytic luminescence intensity of the probe molecule on the surface of the object to be measured, a series of standard slope k values or standard bar codes of the object to be measured are established, and the measured slope k value and bar code of the object to be measured are compared with the standard slope k value or standard bar code one by one. This method has high stability, and the maximum relative deviation is 3.1%.

Description

Technical Field

[0001] The present invention belongs to the field of detection technology, and particularly relates to a method for differentiating talcum powder and talc powder. Background Art

[0002] Talcum powder is an important skin care product in daily life, which has the effects of absorbing sweat, dissipating heat, cleaning, drying, and relieving itching. However, relevant research points out that talcum powder may have a carcinogenic risk. Therefore, it is urgent to monitor the quality of talcum powder.

[0003] At present, the analysis of talc powder and talcum powder is mainly based on methods established by instruments such as SEM, TEM, FT-IR, and XRD. These methods can study the morphology, structure, and chemical and physical properties of substances, but the instruments are expensive, complex, and have high operating costs, making it difficult to achieve low-cost and rapid detection. People expect to establish a rapid and simple detection method.

[0004] The catalytic luminescence sensor has a quartz tube with an air inlet and an air outlet, a ceramic electric heating rod, and a ultra-weak luminescence analyzer equipped with a photomultiplier tube. During detection, the ceramic electric heating rod heats the catalyst on its surface, and O2 generated by the oxygen generator brings volatile organic compounds into the quartz glass tube from the sample inlet. The volatile organic compounds flow through the surface of the ceramic electric heating rod coated with the catalyst, react and then are discharged through the outlet. The light signal generated during the catalytic luminescence process is filtered by the filter and detected by the photomultiplier tube. Currently, gas organic compounds are mainly identified through the catalyst. Solid or powdery substances cannot be used for the catalytic luminescence sensor.

[0005] Therefore, it is necessary to develop a detection method that can identify solids or powders. Summary of the Invention

[0006] The present invention aims to at least solve the above technical problems existing in the prior art. For this purpose, the present invention provides a method for differentiating talcum powder and talc powder.

[0007] The first aspect of the present invention provides a method for differentiating talcum powder and talc powder, including the following steps:

[0008] S100. Obtain the standard slope k value or standard barcode of each standard sample of the analyte according to the following steps;

[0009] S110. Prepare a series of concentrations of probe molecules; or prepare several probe molecules with the same concentration;

[0010] S120. Mix each standard sample of the analyte with a solvent; coat the mixture on a heating element, dry it and then insert it into a quartz tube;

[0011] S130. The carrier gas transports the probe molecules in step S110 into the catalytic luminescence sensor, where they are heated and undergo a catalytic luminescence reaction to obtain a luminescence intensity signal.

[0012] S140. A linear equation is established based on the luminescence intensity signal and a series of concentrations of probe molecules to calculate the slope k value of the analyte standard; alternatively, the luminescence intensity signals generated by several probe molecules with the same concentration are encoded to obtain the analyte standard barcode, and the analyte is judged based on the k value or barcode.

[0013] The analyte is talcum powder or toilet powder.

[0014] One technical solution of the present invention regarding the identification of toilet powder and talcum powder has at least the following beneficial effects:

[0015] The present invention provides a method for detecting and identifying toilet powder and talcum powder through a catalytic luminescence sensor. Based on the catalytic luminescence intensity of the probe molecules on the surface of the analyte, a series of standard slope k values or standard barcodes of the analyte are established, and the measured slope k value and barcode of the analyte are compared one by one with the standard slope k value or standard barcode. This method has high stability, and the maximum relative deviation is 3.1%.

[0016] According to some embodiments of the present invention, the method for judging the analyte based on the k value or barcode is as follows:

[0017] S200. Obtain the slope k value or barcode of the analyte according to the method in step S100.

[0018] S300. Compare the k value or barcode of the analyte obtained in step S200 with the standard k value or standard barcode in step S1 one by one; if they are the same, the analyte is the analyte standard corresponding to the standard k value or standard barcode.

[0019] According to some embodiments of the present invention, in step S110, the probe molecule is at least one of isobutanol, isobutyraldehyde, isovaleraldehyde, propionaldehyde, n-butyraldehyde or n-valeraldehyde.

[0020] According to some embodiments of the present invention, in step S140, the luminescence intensity signals generated by several probe molecules with the same concentration are normalized after background removal, and the first two significant digits of the normalization results of each probe molecule are extracted and arranged in order to form a digital code to obtain the standard barcode.

[0021] According to some embodiments of the present invention, the method and formula for background removal and normalization are as follows:

[0022] Si = I - N, (1);

[0023] S = (Si - Smin) / (Smax - Smin) × 100% (2);

[0024] Where I represents the signal value measured each time, N represents the background value measured, Si represents the net signal obtained by subtracting the background value from the signal value measured each time, Smax represents the maximum signal value in the data, and Smin represents the minimum signal value in the data. After normalization, the relative signal value S is obtained.

[0025] When the reaction temperature is relatively low, the generation of the luminescence signal will decrease; while when the temperature is too high, it will lead to an increase in thermal radiation, resulting in an increase in background noise, thereby reducing the signal-to-noise ratio.

[0026] According to some embodiments of the present invention, in step S130, the heating temperature is 190 - 230 °C.

[0027] According to some embodiments of the present invention, in step S110, the concentrations of the series of probe molecules are 0.5, 1.0, 2.0, 2.5, 4.0, and 5.0 mg / L.

[0028] According to some embodiments of the present invention, in step S110, the same concentration is 16.0 mg / L.

[0029] According to some embodiments of the present invention, in step S120, the solvent includes water.

[0030] When the flow rate of the carrier gas is relatively low, the reaction time becomes longer; when the flow rate of the carrier gas is relatively high, the reaction is incomplete, reducing the luminescence intensity signal value; according to some embodiments of the present invention, in step S130, the delivery rate of the carrier gas is 250 - 350 mL / min.

[0031] When the detection wavelength is relatively small, the luminescence signal value will decrease; while when the detection wavelength is relatively large, the background value increases faster, so the signal-to-noise ratio decreases instead; according to some embodiments of the present invention, in step S130, the detection wavelength in the catalytic luminescence sensor is 400 - 490 nm.

[0032] According to some preferred embodiments of the present invention, in step S130, the detection wavelength in the catalytic luminescence sensor is 425 nm.

[0033] According to some embodiments of the present invention, in step S120, the heating element is a ceramic rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of the device of the catalytic luminescence sensor according to an embodiment of the present invention;

[0035] Among them, 10 is the catalytic luminescence sensing device; 11 is the carrier flow control system; 12 is the sampling system; 5 is the gas inlet; 6 is the gas outlet; 1 is the quartz glass tube; 2 is the heating element; 3 is the filter; 4 is the photomultiplier tube;

[0036] Figure 2 It is the linear relationship diagram between different probe molecules and luminescence intensity in Embodiment 1 of the present invention;

[0037] Figure 3 It is the linear relationship diagram between different probe molecules and luminescence intensity in Embodiment 2 of the present invention;

[0038] Figure 4 It is the relationship diagram between different talcum powder brands and relative luminescence intensity in Embodiment 3 of the present invention;

[0039] Figure 5 It is the relationship diagram between different talc powder particle sizes and relative luminescence intensity in Embodiment 4 of the present invention;

[0040] Figure 6 It is the luminescence intensity signal diagram of continuous testing seven times in Test Example 2;

[0041] Figure 7 It is the luminescence intensity signal diagram of continuous testing seven times in Test Example 3. Specific embodiments

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below, but the embodiments of the present invention are not limited thereto.

[0043] The reagents, methods and equipment adopted in the present invention are all conventional reagents, methods and equipment in the technical field, unless otherwise specified.

[0044] Some raw materials adopted in the following embodiments are as follows:

[0045] Talc powder A: The particle size is 325 mesh; Talc powder B: The particle size is 400 mesh; Talc powder C: The particle size is 800 mesh; Talc powder D: The particle size is 2000 mesh; Talc powder E: The particle size is 3000 mesh; Talc powder F: The particle size is 5000 mesh; (Company: Macklin, CAS number is 14807-96-6, and the product numbers of talc powders with different particle sizes are: T819386-1kg, T819387-1kg, T823197-1kg, T823196-1kg, T823195-1kg, T823198-1kg)

[0046] Talcum powder A: Talcum powder B: Talcum powder C: Talcum powder D: Talcum powder E: Talcum powder F: Talcum powder G: Talcum powder H: Talcum powder I: Talcum powder J: Talcum powder K: Talcum powder L: Purchased from a certain brand on the market.

[0047] The catalytic luminescence system used in the following embodiments consists of a catalytic luminescence sensing device 10, a carrier gas control system 11, and a sampling system 12. The catalytic luminescence sensing device 10 is composed of a quartz glass tube 1 with a gas inlet 5 and a gas outlet 6, a ceramic heating rod 2, a filter 3, and a photomultiplier tube 4 (see Figure 1 ).

[0048] Example 1

[0049] Example 1 provides a method for identifying talcum powder, which includes the following steps:

[0050] S100. Obtain the standard slope k values of 12 talcum powder standards according to the following steps;

[0051] S110. Prepare propionaldehyde at concentrations of 0.5, 1.0, 2.0, 2.5, 4.0, and 5.0 mg / L as probe molecules respectively;

[0052] S120. Weigh 0.5 g of each talcum powder standard, mix it with 0.5 mL of water, and ultrasonicate; coat the mixture on a ceramic rod, dry it, and insert it into a quartz tube;

[0053] S130. Use carrier gas oxygen to transport the propionaldehyde in step S110 to the catalytic luminescence sensor, heat it to 210 °C and carry out a catalytic luminescence reaction to obtain a luminescence intensity signal; the oxygen flow rate is 300 mL / min;

[0054] S140. Establish a linear equation based on the luminescence intensity signal and a series of concentrations of propionaldehyde, calculate the slope k value of the analyte standard, and judge the talcum powder brand according to the k value.

[0055] Through Figure 2 the linear relationship diagram, calculate the slope k value of each brand, as shown in Table 1.

[0056] Table 1 Slope k values of talcum powder

[0057]

[0058] Example 2

[0059] Example 2 provides a method for identifying talc powder. The identification method is the same as that in Example 1, except that the analyte is talc powder. Through Figure 3 the linear relationship diagram, calculate the slope k value of each talc powder particle size, and the specific values are shown in Table 2.

[0060] Table 2 Slope k values of talc powder

[0061]

[0062]

[0063] Example 3

[0064] Example 3 provides a method for identifying talcum powder, including the following steps:

[0065] S100. Obtain the standard barcodes of 12 talcum powder standards according to the following steps;

[0066] S110. Prepare isobutanol, isobutyraldehyde, isovaleraldehyde, n-propionaldehyde, n-butyraldehyde, and n-valeraldehyde (with concentrations of 16.0, 1.6, 16.0, 16.0, 16.0, and 16.2 mg / L respectively) as 6 probe molecules;

[0067] S120. Mix each test talcum powder standard with water and ultrasonicate; coat the mixture on a ceramic rod, dry it, and insert it into a quartz tube;

[0068] S130. Use the carrier gas oxygen to transport the 6 probe molecules in step S110 to a catalytic luminescence sensor, heat it, and perform a catalytic luminescence reaction to obtain luminescence intensity signals respectively; the oxygen flow rate is 300 mL / min;

[0069] S140. Normalize the luminescence intensity signals generated by the 6 probe molecules with the same concentration after removing the background, extract the first two significant digits of the normalization results of each probe molecule in order to form a digital code, and obtain the standard barcode.

[0070] The results are as Figure 4 shown, a series of talcum powder barcode diagrams of different brands are obtained, and the brand of the test talcum powder is judged according to the talcum powder barcode diagrams of different brands. The results obtained are consistent with the actual situation.

[0071] Example 4

[0072] Example 4 provides a method for identifying talc powder. The identification method is the same as that in Example 3, except that the test substance is talc powder and there are 6 talc powder standards.

[0073] The results are as Figure 5 shown, a series of standard barcodes of talc powder with different particle sizes are obtained, and the particle size of the test talc powder is judged according to the barcode diagrams of the particle sizes of talc powder of different brands.

[0074] Test Example 1

[0075] Test Example 1 provides a method for detecting talcum powder, aiming to evaluate the stability of the luminescence intensity signal of the detection method.

[0076] Weigh 0.5 g of talcum powder A, stir and ultrasonicate it in 0.5 mL of water, and then evenly coat it on the surface of a ceramic heating rod.

[0077] Prepare a 5.0 mg / L n-propionaldehyde gas by the headspace gas preparation method as the probe molecule.

[0078] Turn on the temperature controller, control the ceramic rod at 210 °C, the oxygen generator delivers oxygen to the chemiluminescence reaction chamber, and the oxygen flow rate is 300 mL / min to obtain a balanced baseline and read the background value.

[0079] Injection for detection

[0080] Use a gas injection needle to take 1.0 mL of gas and inject it into the three-way injection valve. The carrier gas brings the gas probe molecule into the chemiluminescence reaction chamber, reacts with O2 to generate a luminescence intensity signal. The luminescence signal is spectroscopically analyzed by a 425 nm filter and detected by a photomultiplier tube and converted into an electrical signal for recording. The n-propionaldehyde gas with a concentration of 5.0 mg / L is determined in parallel 7 times, and the relative standard deviation of the 7 parallel determinations is 2.8%, indicating that the detection method of the present invention has good stability.

[0081] Test Example 2

[0082] Test Example 2 provides a method for detecting talcum powder, aiming to detect the stability of 7 batches of the same kind of talcum powder. The detection method is the same as that in Test Example 1. Under the same conditions, the n-propionaldehyde gas with a concentration of 5.0 mg / L passes through 7 batches of the same kind of talcum powder, and the test results are as Figure 6 shown.

[0083] From Figure 6 it can be seen that the relative standard deviation of the 7 determinations is 2.9%, indicating that the detection method of the present invention has good stability.

[0084] Test Example 3

[0085] Test Example 3 provides a method for detecting talcum powder, aiming to detect the k-value stability of 7 batches of the same kind of talcum powder. The detection method is the same as that in Test Example 1. Using talcum powder as a catalyst, prepare n-propionaldehyde with concentrations of 0.5, 1.0, 2.0, 2.5, 4.0, and 5.0 mg / L respectively. Referring to the detection method in Example 5, under the same conditions, the n-propionaldehyde gas of each concentration passes through 7 batches of the same kind of talcum powder, and the k-values of each batch of talcum powder after testing are as Figure 7 shown.

[0086] The relative standard deviation of the k-values of the 7 batches is 3.1%, indicating that the detection method of the present invention has good stability.

[0087] From Figure 7 it can be seen that the relative standard deviation of the k-values of the 7 batches is 3.1%, indicating that the detection method of the present invention has good stability.

[0088] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A method for differentiating talcum powder and talc, characterized in that, It includes the following steps: S100. Obtain the standard slope k value or standard barcode of each analyte standard according to the following steps; S110. Prepare a series of concentrations of probe molecules; or prepare several probe molecules with the same concentration; S120. Mix each analyte standard with a solvent; coat the mixture on a heating element, dry it and insert it into a quartz tube; S130. The carrier gas transports the probe molecules in step S110 to a catalytic luminescence sensor, heats them and performs a catalytic luminescence reaction to obtain a luminescence intensity signal; S140. Establish a linear equation based on the luminescence intensity signal and a series of concentrations of probe molecules to calculate the slope k value of the analyte standard; or encode the luminescence intensity signals generated by several probe molecules with the same concentration to obtain the analyte standard barcode, and judge the analyte according to the k value or barcode; The analyte is talcum powder or toilet powder; In step S110, the probe molecule is at least one of isobutanol, isobutyraldehyde, isovaleraldehyde, propionaldehyde, n-butyraldehyde or n-valeraldehyde.

2. The method for identifying talcum powder and talc according to claim 1, wherein In step S140, the luminescence intensity signals generated by several probe molecules with the same concentration are normalized after removing the background, and the first two significant digits of the normalization results of each probe molecule are extracted and arranged in order to form a digital code to obtain the standard barcode.

3. The method for differentiating talcum powder and French chalk according to claim 1, characterized in that, In step S130, the heating temperature is 190-230 °C.

4. The method for differentiating talcum powder and French chalk according to claim 1, wherein, In step S110, the concentrations of the series of probe molecules are 0.5, 1.0, 2.0, 2.5, 4.0 and 5.0 mg / L.

5. The method for identifying talcum powder and talc according to claim 1, wherein In step S110, the same concentration is 16.0 mg / L.

6. The method for differentiating talcum powder and French chalk according to claim 1, wherein, In step S120, the solvent includes water.

7. The method for identifying talcum powder and talc according to claim 1, characterized in that, In step S130, the transport rate of the carrier gas is 250-350 mL / min.

8. The method for identifying talcum powder and French chalk according to claim 1, wherein In step S130, the detection wavelength in the catalytic luminescence sensor is 400-490 nm.

9. The method for identifying talcum powder and talc according to claim 1, characterized in that, In step S120, the heating element is a ceramic rod.

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