Chemicals and Reagents . All solven

Chemicals and Reagents . All solvents, including acetone,
n-hexane, methanol, and dichloromethane, were of HPLC
grade and purchased from Tedia Co., USA. Water was
purified with an ultrapure water system (Purelab UHQ, Elga
LabWater, UK). Silica gel (100–200 mesh, reagent grade,
Qingdao Ocean Chemical Reagent Co., China), anhydrous
sodium sulfate (analytical grade, Chongqing Kelong Chemical
Reagent Co., China), and glass fiber filters (0.45