Analysis of X-ray diffraction fingerprint of Calamina and its processed products / 中草药

Objective: To establish X-ray diffraction (XRD) fingerprint of Calamina and its processed products, compare the effects of different processing Methods on the main components of medicinal materials and determine the content of ZnO in the processed products. Methods: XRD was used to analyze 10 batches of Calamina and its processed products, and fingerprints of Calamina and its processed products were established respectively. Six different processing methods were compared, and the content of ZnO in all processed products was determined by K value method. Results: Fingerprints of Calamina and its processed products were preliminarily established. There were 23 common peaks in the fingerprints of Calamina, and there were 10 common peaks in the fingerprints of its processed products. After calcination, the ZnCO3 characteristic peak of the raw material was transformed into the characteristic peak of ZnO; The content of ZnO in the calcined product exceeded 56%. Conclusion: XRD fingerprints could be used for the identification and analysis of Calamina and its processed products. The new and reliable method was provided for quality evaluation of Calamina and its processed products.

Study on quality status of mineral medicine Calamina / 中国中药杂志

In this paper, some quality problems of mineral medicine Calamina and calcined Calamina have been discussed after determination and analysis of the quality parameters of a large number of market samples, and the countermeasures are put forward. According to the XRD results, as well as the results of tests included in Chinese Pharmacopoeia(2015 edition), the authenticity of Calamina and calcined Calamina samples were identified. The content of zinc oxide in samples were determined by the method of determination in Chinese Pharmacopoeia. Individually, inductively coupled plasma mass spectrometry(ICP-MS), inductively coupled plasma atomic emission spectrometry(ICP-AES) and atomic fluorescence spectrometry(AFS) methods were used for the determination of impurity elements and harmful elements in Calamina and calcined Calamina samples. Four kinds of impurity elements of magnesium(Mg), iron(Fe), aluminum(Al), calcium(Ca) and five harmful elements such as lead(Pb), cadmium(Cd), arsenic(As), copper(Cu), mercury(Hg) were measured. The study showed that: ① Fake Calamina products on the market were overflowing; ② The mineral origin of the mainstream Calamina in the market is inconsistent with that stipulated in Chinese Pharmacopoeia(2015 edition); ③ The contents of harmful elements Pb and Cd in Calamina and calcined Calamina are generally higher, while the contents of harmful elements As and Cu in some inferior Calaminae are higher; ④ Parts of calcined Calamina were improperly or inadequately processed. In view of these quality problems, the countermeasures are put forward as follows: ① It is suggested that hydrozincite should be approved as the mineral source of Calamina, and be included by Chinese Pharmacopoeia; ② Strengthen the research on the specificity of Calamina identification methods to improve the quality control level; ③ Strengthen the research on the processing of Calamina, and formulate the limit standards for the content of Pb and Cd in Calamina; ④ Carry out research on the artificial synthesis of Calamina and calcined Calamina, in order to cope with the current shortage of Calamina resources and ensure the sustainable development of Calamina medicinal materials.

Rapid Identification of Calamina Based on Near-infrared Diffuse Reflectance Spectroscopy and PCA-SVM Algorithm / 中国实验方剂学杂志

Objective: To establish a near-infrared diffuse reflectance spectroscopy(NIRS) identification model for crude products,counterfeit products and processed products of Calamina by principal component analysis(PCA) and support vector machine(SVM) algorithm. Method: NIRS of crude products,counterfeit products and processed products of Calamina were collected,the characteristic spectrum segments were selected,the preprocessing method and the optimum principal component number were optimized,and the PCA-SVM qualitative model was established. Result: The characteristic spectrum segment of analysis model was 7 500-4 000 cm-1.Spectra were preprocessed by the first-order derivative method(FD).The optimum principal component number was 5. And the optimum internal parameters of SVM[penalty factor(c)=0.25 and kernel function parameter(g)=8] were screened by applying the grid search algorithm.In the PCA-SVM qualitative model,the prediction accuracy rate was 100%for the 5-fold cross validation,and the prediction accuracy rates also were 100%both for training set and test set. Conclusion: PCA-SVM analysis model of NIRS for Calamina samples has a high prediction accuracy rate,and it can be used for the rapid and nondestructive identification of crude products,counterfeit products and processed products of Calamina by combining the diffuse reflection technique on solid powder.