RESUMO
Objective: The effect of ethanol to material ratio on ethanol precipitation and sediment morphology of Shuanghuanglian preparation (SHLP) were researched, and the feasibility of comprehensive evaluation of ethanol precipitation sediment fractal dimension was discussed. Methods: For the SHLP ethanol precipitation process, HPLC and gravimetric analysis were used to investigate the effects of ethanol to material ratio on the overall retention of the index components and the liquid content of the filter cake. The direct observation, atomic force microscope observation and "area-perimeter" calculation method were used to investigate the influence of ethanol to material ratio on the apparent morphology, micro-morphology and fractal dimension of the precipitate. At the same time, Pearson correlation analysis method was used to investigate the correlation between the fractal dimension and the above evaluation index of ethanol precipitation effect. Results: With the increase of the ethanol to material ratio, the comprehensive retention of the index components and the fractal dimension of the ethanol precipitation precipitates was gradually increased, while the liquid content of the filter cake was gradually decreased. Therefore, the fractal dimension of sediment was positively correlated with the comprehensive retention rate of index components, but negatively correlated with the liquid content of the filter cake. Conclusion: The fractal dimension of ethanol precipitation sediment can be used as comprehensive evaluation index for reflecting the ethanol precipitation effect in the SHLP ethanol precipitation process, which can provide a reference for the visualized fine control research of the subsequent SHLP ethanol precipitation process.
RESUMO
Objective: To establish a method for the determination of fractal dimension of ethanol precipitation flocs in two kinds of root medicinal herbs (Astragali Radix and Isatidis Radix). Method: The ethanol-precipitated flocs of Astragali Radix and Isatidis Radix were taken as the research objects. Firstly, the original microscopic images of the ethanol precipitation flocs were binarized by Ostu algorithm. Secondly, the influence of sampling volume, dilution multiple, image magnification ratio and number of image acquisition sites on fractal dimension was investigated using perimeter-area method. Result: The ethanol precipitation flocs of Astragali Radix and Isatidis Radix had fractal characteristics. At the same time, the stable and reliable fractal dimension of the flocs could be obtained when the sampling volume was 600-800 μL, the sample was diluted to 5-20 times, the microscopic image was enlarged to 200 times or 400 times, and four different image acquisition sites were selected. Conclusion: The established method is stable and feasible, which can provide reference for the fractal theory of ethanol precipitation flocs of root medicinal herbs.