Recent advances of modern sample preparation techniques for traditional Chinese medicines

Traditional Chinese medicines (TCMs) have been widely applied to the prevention and treatment of various illnesses for thousands of years. Sample preparation played a crucial role in the analysis of TCMs because of the complexity of the sample matrixes. In this paper, recent developments and applications of modern sample preparation techniques for the analysis of TCMs were summarized. The sample preparation techniques to pretreat herbal matrixes included ultrasound-assisted extraction, microwave-assisted extraction, pressurized-liquid extraction, supercritical-fluid extraction, synergistic extraction techniques and so on. The sample preparation techniques mainly applied to pretreating biological matrixes such as microdialysis and microfluidic technique were presented. The sample preparation techniques applied to both herbal and biological matrixes were discussed as well, involving solid phase extraction, matrix solid phase dispersion, solid phase microextraction, cloud point extraction, online coupling sample preparation techniques and so on. In addition, the trends for sample preparation techniques of TCMs were proposed.