Method for identifying authenticity and origin of <i>Panax quinquefolius </i>based on terahertz spectroscopy

Abstract

Provided is a method for identifying authenticity and origin of Panax quinquefolius based on terahertz spectroscopy. The time domain spectral information of the Panax quinquefolius sample is obtained, and converted into the frequency domain spectral information by Fourier transform to calculate a terahertz absorption spectrum. The identification is performed by observing whether there are characteristic absorption peaks of pseudoginsenoside F11 in the terahertz absorption spectrum.

Claims

1. A method for identifying authenticity and origin of Panax quinquefolius based on terahertz spectroscopy, comprising: (1) pulverizing a Panax quinquefolius sample by a pulverizer followed by mixing it with a powder of a material with a terahertz transmittance in proportion to produce a powder mixture, and then compressing the powder mixture into a tablet by a tablet press; (2) reducing a humidity in a sample chamber of a terahertz spectrometer to 3%, and collecting a time domain spectral information of a tablet of the material with terahertz transmittance as thick as the tablet obtained in step (1) as a background; (3) placing the tablet obtained in step (1) on the a sample holder followed by analysis to obtain a time domain spectral information of the tablet obtained in step (1), and converting the time domain spectral information of the tablet obtained in step (1) into frequency domain spectral information by Fourier transform to calculate a terahertz absorption spectrum; (4) observing whether there are absorption peaks at 1.76 THz, 3.11 THz, and 3.61 THz specific to Panax quinquefolius in the terahertz absorption spectrum; and wherein if there are absorption peaks at 1.76 THz, 3.11 THz and 3.61 THz, the Panax quinquefolius sample is determined to be true Panax quinquefolius ; and (5) observing whether there is an absorption peak at 2.53 THz in the terahertz absorption spectrum after confirming that the Panax quinquefolius sample is ture Panax quinquefolius; and determining that an origin of the Panax quinquefolius is China if there is an absorption peak at 2.53 THz, otherwise determining that the origin of the Panax quinquefolius is North America.

2. The method of claim 1, wherein the absorption peaks at 1.76 THz, 3.11 THz, and 3.61 THz are characteristic peaks of pseudoginsenoside F11 in Panax quinquefolius.

3. The method of claim 1, wherein in steps (1) and (2), the material with terahertz transmittance is polyethylene.

4. The method of claim 1, wherein in step (1), the Panax quinquefolius sample is in a form of original material, powder, preparation, liquid or lozenge.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a characteristic spectrum of Chinese Panax quinquefolius obtained by a method according to an embodiment of the present disclosure;

(2) FIG. 2 is a characteristic spectrum of North America Panax quinquefolius obtained by the method according to an embodiment of the present disclosure; and

(3) FIG. 3 is a characteristic spectrum of pseudoginsenoside F11.

DETAILED DESCRIPTION OF EMBODIMENTS

(4) The present disclosure will be described in detail below with reference to the drawings and embodiments. The detailed implementation of the technical solutions of the present disclosure is described in the following embodiments. It should be understood that these embodiments are merely illustrative of the present disclosure, and are not intended to limit the scope of the present disclosure.

(5) This application provides a method for identifying authenticity and origin of Panax quinquefolius based on terahertz spectroscopy, which can quickly, cost-effectively and easily identify the origin of the Panax quinquefolius and determine a content of key ingredients of the commercially-available Panax quinquefolius drugs.

(6) The method has the following steps.

(7) 1. A Panax quinquefolius sample is pulverized by a pulverizer and mixed with a powder of a material with a high terahertz transmittance in proportion, and then the mixture is compressed into a tablet by a tablet press, where the material with a high terahertz transmittance can be polyethylene, cycloolefin polymer or other materials with high terahertz transmittance.

(8) 2. Humidity in a sample chamber of a terahertz spectrometer is reduced to 3% or less to measure a background in a single channel, and a time domain spectral information of a polyethylene tablet as thick as the tablet of the mixed powder is collected as the background.

(9) 3. The tablet obtained in step (1) is placed on a sample holder followed by analysis to obtain a time domain spectral information of the tablet obtained in step (1), and the time domain spectral information of the tablet obtained in step (1) is converted into frequency domain spectral information by Fourier transform to calculate a terahertz absorption spectrum. The calculation formula is Ab=−log(Sam/Ref); where Ab is an absorption data, Sam is a frequency domain spectral data, and Ref is a reference frequency domain spectral data.

(10) 4. The absorption spectrum data of the Panax quinquefolius sample is analyzed, and whether there are absorption peaks at 1.76 THz, 3.11 THz, and 3.61 THz specific to Panax quinquefolius in the terahertz absorption spectrum is observed to judge the authenticity of the Panax quinquefolius contained in the sample. The characteristic spectrum of the Chinese Panax quinquefolius is shown in FIG. 1, there are absorption peaks at 1.76 THz, 3.11 THz, and 3.61 THz, the Panax quinquefolius sample is determined to be true Panax quinquefolius.

(11) 5. After the sample is confirmed to be a ture Panax quinquefolius, whether there is an absorption peak at 2.53 THz in the terahertz absorption spectrum is observed to determine the origin of the Panax quinquefolius. Comparing FIG. 1 and FIG. 2, the difference between the two kinds of Panax quinquefolius is the absorption peak at 2.53 THz. The origin of the Panax quinquefolius is determined to China if there is an absorption peak at 2.53 THz, otherwise the origin of the Panax quinquefolius is determined to North America.

EXAMPLE 1

(12) Instruments: terahertz spectrospectrometer, electronic scale, pulverizer, tablet press and grinding dish.

(13) Samples: Chinese Panax quinquefolius samples, North America Panax quinquefolius samples and polyethylene powder (PE);

(14) The preparation of a test sample was described as follows.

(15) The Panax quinquefolius sample was pulverized by the pulverizer to obtain a sample powder. An appropriate amount of the sample powder was weighed using an electronic scale and mixed with polyethylene powder in a grinding dish, where a mass ratio of the sample powder to the polyethylene powder was 6:1. Then, the powder mixture was compressed into a sample tablet in a tablet press with a force of 3 tons for 3 min, which was then analyzed by the terahertz spectrometer.

(16) (1) Humidity in the sample chamber of the terahertz spectrometer was reduced to 3% or less to measure a background in a single channel, and a time domain spectral information of a polyethylene tablet as thick as the tablet of the mixed powder was collected as the background.

(17) (2) The sample tablet was placed on the sample holder followed by analysis to obtain a time domain spectral information of the sample tablet, and the time domain spectral information of the sample tablet was converted into frequency domain spectral information by Fourier transform to calculate a terahertz absorption spectrum.

(18) $\mathrm{Ab}=-\log \left(\frac{\mathrm{Sam}}{\mathrm{Ref}}\right);$

(19) The calculation formula was where Ab was absorption data, Sam was frequency domain spectral data, and Ref was reference frequency domain spectral data.

(20) (3) The absorption spectrum data of the Panax quinquefolius sample was analyzed, and whether there are absorption peaks at 1.76 THz, 3.11 THz, and 3.61 THz specific to Panax quinquefolius in the terahertz absorption spectrum was observed to judge the authenticity of the Panax quinquefolius contained in the sample. Whether there is an absorption peak at 2.53 THz in the terahertz absorption was observed after confirming that the Panax quinquefolius sample is true Panax quinquefolius. An origin of the Panax quinquefolius is determined to China if there is an absorption peak at 2.53 THz, otherwise the origin of the Panax quinquefolius is determined to North America.

(21) The Panax quinquefolius sample can be in a form of original material, powder, preparation, liquid or lozenge.

(22) Pseudoginsenoside F11 was a saponin specific to Panax quinquefolius, and its characteristic spectrum was shown in FIG. 3. In the method of the disclosure, the identification of Panax quinquefolius is performed by observing whether there were three characteristic peaks (1.76 THz, 3.11 THz and 3.61 THz) of the pseudoginsenoside F11 in the terahertz absorption spectrum of the sample. The conventional Panax quinquefolius identification did not involve the terahertz absorption peaks of pseudoginsenoside F11. In addition, the absorption peak at 2.53 THz is specific to Chinese Panax quinquefolius. Other terahertz analysis methods of medicines did not propose the use of three characteristic peaks (1.76 THz, 3.11 THz, 3.61 THz) of pseudoginsenoside F11 for identification of Panax quinquefolius and the characteristic peak at 2.53 THz for the identification of origin, failing to enable effective detection of Panax quinquefolius.