Quality evaluation of Hawk tea from different months and regions based on quantitative analysis of multiple components with a single marker (QAMS) combined with HPLC fingerprint.

BACKGROUND: Hawk tea, a medicinal and edible plant, has been consumed for thousands of years in Southwest China. To date, no unified food safety standard for Hawk tea has been established, and systematic research on the quality of Hawk tea is lacking. OBJECTIVE: The aim of this study was to develop a comprehensive evaluation method for the quality of Hawk tea based on inclusions content, high-performance liquid chromatography (HPLC) fingerprinting combined with the quantitative analysis of multiple components with a single marker (QAMS) method. METHODS: The contents of total flavonoids, total phenols, total polysaccharides, and total protein were determined using the colorimetric method. An effective comprehensive evaluation method was established to classify the 16 batches of samples based on HPLC fingerprint analysis combined with similarity analysis (SA), hierarchical cluster analysis (HCA), principal component analysis (PCA), partial least-squares discrimination analysis (PLS-DA), and the QAMS method. RESULTS: Flavonoids were the main chemical components of Hawk tea. The accuracy of the QAMS method was verified by comparing the calculated results with those of the external standard method (ESM). No significant differences were found between the two methods. Additionally, the fingerprint of Hawk tea was also established. CONCLUSION: The method established in this study can be used for the comprehensive quality evaluation of Hawk tea and can also provide a reference for the quality evaluation of other herbal medicines.

[Solubilization thermodynamics and kinetics of anthracene in the presence of humic acid].

The solubilization thermodynamics and kinetics characteristics of hydrophobic pollutants anthracene in the humic acid micellar solutions have been investigated by using batch equilibrium test. The results showed that the solubilization rate of anthracene was significantly enhanced with increasing temperature. The solubilization process of anthracene was spontaneous, endothermic and entropy increasing with deltaG(theta) = -1.682 kJ/mol, deltaH(theta) = 11.96 kJ/mol, deltaS(theta) = 45.78 J/(K x mol) in 25 degrees C, as well as deltaG(theta) = -2.140 kJ/mol and -2.598 kJ/mol in 35 degrees and 45 degrees C, respectively. The solubilization data of anthracene well fitted Elovich kinetics model.