| The production process of Traditional Chinese medicine(TCM) is composed of a series of unit operations. Among them the extraction of TCM whose endpoint determination directly affects the effectiveness and stability of TCM is one of the most important parts. This paper adopts ultraviolet spectroscopy technology to determine the endpoint of mostly TCM extractions. Based on this theory, we developed an online analysis system suitable for industrial application of the extraction process of TCM. The main work includes:(1)Feasibility study of UV spectrum. Firstly, building two experimental platforms (NIR and UV) and measuring the extracts of5kinds of TCM such as ginkgo biloba leaves, lonicera japonica. The experimental results show that:for the low content effective substances in water, the UV spectroscopy has better sensitivity and signal to noise ratio than NIR, and has a good linear relationship between the concentration and absorbance. But for the high concentration, it should be diluted before measurement. Based on the above experimental results, we sampled off-line in the Chinese medicine extract workshop and measured the UV spectrum. Through the processing and analysis of the spectrum, we found that the characteristic peak’s absorbance can reflect the change trend of extraction process.(2)Development and manufacturing of on-line analysis system for the TCM extraction. The hardware mainly includes5parts:pretreatment device, automatic sampling device, optical system, PLC control system, data transmission and remote monitoring device. Among them, the pretreatment device is responsible for filtration and cooling; the automatic sampling device is responsible for extracts sampling and proportional dilution; the optical system is responsible for UV spectrum measurement; the PLC control system is in charge of the temperature detection and control of light source, electromagnetic valve and motor; the data transmission and remote monitoring device is in charge of data transmission, image display and the trend analysis. The software includes slave computer parts and host computer parts. The slave computer software is installed in PLC and responsible for sending temperature signal to host computer and receiving commands to control light source, motor etc. The host computer software is installed in industrial PC and responsible for the whole process control and spectral sampling, processing, displaying, analyzing etc. (3)The system has been successfully applied in industrial field. It has been installed in the Chinese medicine extract workshop of Beijing Tcmages Pharmaceutical Co., LTD. The system has been completed monitoring for more than50kinds of Chinese medicinal materials and200batches of extraction process. The results compared with off-line analysis show that:the system has high reliability and repeatability, can reflect the trend of extraction process and complete endpoint determination. |
PDF Full Text Request