The paper is to report the development of a high-performance liquid chromatographic/tandem mass spectrometry (HPLC-MS/MS) method for the determination of icaritin (ICT) in rat plasma. After precipitated with acetonitrile from the plasma, ICT was isolated chromatographically on a Dikma C18 column. The mobile phase consisted of acetonitrile-water-acetic acid (72 : 28 : 1.5, v/v/v). Electrospray ionization (ESI) source was applied and operated in the positive ion mode. Multiple reaction monitoring (MRM) mode with the transitions of m/z 387 --> m/z 313 and m/z 331 --> m/z 315 were used to quantify ICT and the internal standard, respectively. The linear calibration curve was obtained in the concentration range of 2.5-1,000 ng x mL(-1). The lower limit of quantification was 2.5 ng x mL(-1). The inter- and intra-day precision (RSD) were less than 9.63%, and the accuracy (relative error) was within +/-7.42%. The method was proved to be suitable for the pharmacokinetics of ICT, which offers advantages of high sensitivity and selectivity.
Administration, Oral ; Animals ; Chromatography, High Pressure Liquid ; methods ; Epimedium ; chemistry ; Female ; Flavonoids ; administration & dosage ; blood ; isolation & purification ; pharmacokinetics ; Male ; Plants, Medicinal ; chemistry ; Rats ; Rats, Wistar ; Reproducibility of Results ; Sensitivity and Specificity ; Spectrometry, Mass, Electrospray Ionization ; methods ; Tandem Mass Spectrometry ; methods

Objective To explore the relationships between the polyrnorphisms of xeroderma pigmentosum A(XPA) and the susceptibility of esophageal cancer (EC),as well as its interaction with environmental factors-gene in Changzhi area,Shanxi province. Methods A case-control study was conducted,including 196 cases of EC and 201 controls.XPA 23G polymorphisms were determined with polymerase chain-restriction on fragment length polymorphism (PCR-RFLP).Results The risk of EC was significantly degraded in the individuals who had been carrying the XPA heterozygote (A/G) and mutation genotype (G/G),compared to those with wild genotype (X2=16.21,P＜0.01) and the ORs were 0.58 (0.37-0.91) and 0.32 (0.18-0.56),respectively.There was negative interaction between XPA 23G mutation genotype and the consumption of pickled food (S=0.04,API=-0.77).Conclusion Genetic polymorphism in the XPA 23G might be associated with esophageal cancer in Changzhi area,and there was a negative action between XPA predisposing genotype and the consumption of pielded food.