Search

Abstract: Objective: To establish reliable methods for evaluating the quality of Chinese herb fructus chaenomelis. Methods: Qualitative analysis by Thin layer chromatography (TLC), reference substances were Chaenomeles speciosa (Sweet) Nakai and oleanolic acid, a mixed solvent of chloroform-methanol (40:1) was employed as the mobile phase, color developing agent was 10% sulfuric acid-ethanol solution. In the system of high performance liquid chromatography (HPLC), a Prontosil Eurobond C18 column (250 mmx4.0 mm, 5 μm) was used, the mobile phase was composed of acetonitrile-methanol-0.4% ammonium acetate solution (55:25:20), the flow rate was 1.0 ml/min with UV detected at 210 nm, the column temperature was maintained at room temperature. Results: In the system of TLC, oleanolic acid was separated successfully. In HPLC, the linear ranges of oleanolic acid and ursolic acid were 5.89±13.73 μg (R=0.9990) and 6.84±15.96 μg (R=0.9990), respectively. The average recoveries of oleanolic acid and ursolic acid were 97.52% (RSD=2.58%), 98.21% (RSD=2.23%), respectively. Conclusion: The established TLC method can easily distinguish Chinese herb fructus chaenomelis from other commonly used crude drugs of the same family. The HPLC method for determining oleanolic acid and ursolic acid is simple, reproducible, accurate and feasible. The methods reported in this paper can be used scientifically and effectively to evaluate the quality of Chinese herb fructus chaenomelis. [Copyright &y& Elsevier]

Abstract: In this paper, the molecularly imprinted polymer layer of estriol at the silica nanoparticles surface with selective recognition had been constructed. The methacryl groups of functional monomer at the silica nanoparticles surface were acted as reactive sites to induce imprinting polymerisation. The absorption capacity results showed that the molecularly imprinted polymers had an excellent combining affinity, recognition selectivity and fast kinetics. Furthermore, the molecularly imprinted polymers were successfully used as absorbent of dispersive solid-phase extraction coupled with high-performance liquid chromatography to determinate trace estriol and estradiol in milk tablets. The high recoveries yielded of 89.1–93.5% were achieved with the relative standard deviations less than 9.4%. So, the molecularly imprinted polymers are the effective absorbents for the separation and enrichment of oestrogens in the complex matrices samples. [Copyright &y& Elsevier]