Studies On The Separation And Analysis Of Drugs In Biological Fluids Using Liquid Phase Microextraction Combined With High Performance Liquid Chromatograhy

Liquid phase microextraction (LPME) is a new sensitive, suitable and environmental friendly sample pretreatment technique based on the excellent anti-interfering and excellent enrichment character. The technique of LPME combined with high performance liquid chromatography (HPLC) has been widely applied to phytochemistry, analytical chemistry, biochemistry, environmental control, clinical medicine, pharmacological researches, and so on. In the present paper, the separation and analysis of drugs in biological fluids using liquid-liquid-liquid microextraction (LLLME) combined with HPLC have been systematically studied. The details are summarized as follows:1. The review of several sample pretreatment methods, especially in LPME.2. LLLME-HPLC was developed for the simultaneous determination of three kinds of local anaesthetics, lidocaine, bupivacaine, and tetracaine in human plasma. Relevant parameters, the stirring rate, the extraction time, and pH in the donor phase were optimized. The method has provided high selectivity and excellent anti-interfering ability for the simultaneous determination of lidocaine, bupivacaine, and tetracaine in human plasma and the optimized method was successfully applied to specimen of patient who was treated with lumbar and extradural anaesthesia of lidocaine and bupivacaine.3. LLLME-HPLC was proposed for the determination of diethylstilbeostrol in human urine. Relevant parameters, the extraction solvent, the volume of the organic phase, the stirring rate, the extraction time, the pH in the donor phase and theconcentration of the acceptor phase were optimized. The method has provided high selectivity for the determination of diethylstilbeostrol in human urine.4. LLLME-HPLC was developed for the simultaneous determination of sildenafil and varndinafil in human plasma. Relevant parameters, the extraction solvent, the volume of the organic phase, the volume of the droplet, the stirring rate, and the extraction time were optimized. The method has provided high selectivity for the simultaneous determination of sildenafil and varndinafil in human plasma.5. Carrier mediated-transport LLLME-HPLC was developed for the simultaneous determination of hydrophilic drugs, morphine and ephedrine and hydrophobic drug, pethidine, in human urine. Extraction efficiency of morphine and ephedrine has been greatly increased by adding carrier into the organic phase. The results indicate that LLLME by adding carrier to the organic phase can be successfully applied to the separation and enrichment of hydrophilic drugs, and the applied range of the liquid phase microextraction has been expanded.