Cloud Point Extraction-HPLC Determination of Polycyclic Aromatic Hydrocarbons Residues in Traditional Chinese Medicinal Herbs

A method was developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) residues in traditional Chinese medicinal herbs by using cloud point extraction combined with high performance liquid chromatography- fluorescence detection. Non-ionic surfactant Genapol X-080 was used for the cloud point extraction of five PAHs residues. Some important parameters influencing the extraction efficiency, such as the surfactant concentration, ultrasonic-assisted extraction time, liquid to solid ratio, salt concentration as well as the equilibration time and temperature, were investigated in detail. Experimental results showed that good linearity could be obtained in the concentration range of 0.05-20ng/ml for all the five PAHs with correlation coefficients between 0.9989 and 0.9999. Relative standard deviations for five replicate determinations of PAHs were between 4.6-6.6%. The established method has been successfully applied to the determination of PAHs residues in Rehmannia, Radix Isatidis, Rhizoma Coptidis, Root of Auricledleaf Swallowwort and Radix Scutellariae.