ABSTRACT
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.