Relative bioavailability of Ophiopogon japonicus saponin enteric microsphere in rats Determination of iridoid glycosides in Lonicerae Japonicae Flos and its patent medicine Lianhua Qingwen Capsule by dispersive solid phase extraction-HPLC Residues Analysis and Degradation Dynamic of Organophosphorus Pesticides in Citrus Fruits Residues Analysis and Degradation Dynamic of Organophosphorus Pesticides in Citrus Fruits Determination of 2,4-D Acid Residues in Four Kinds of Vegetables and Fruits by Solid Phase Extraction and High Performance Liquid Chromatography Studies on solid phase extraction method of aristolochic acids and aristololactams in rat urine Analysis of alkaloids in Nelumbo nucifera leaves by solid phase extraction-rapid resolution liquid chromatography-quadrupole-time of flight mass spectrometry Analysis of alkaloids in Nelumbo nucifera leaves by solid phase extraction-rapid resolution liquid chromatography-quadrupole-time of flight mass spectrometry Determination of gelsemine and koumine in human plasma by HPLC-UV