The applicability of hollow fiber liquid-phase microextraction (HF-LPME) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was evaluated for the extraction and determination of tamox...The applicability of hollow fiber liquid-phase microextraction (HF-LPME) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was evaluated for the extraction and determination of tamoxifen (TAM) in biological fluids including human urine and plasma. The drug was extracted from a 15 mL aqueous sample (source phase;SP) into an organic phase impregnated in the pores of the hollow fiber (membrane phase;MP) followed by the back-extraction into a second aqueous solution (receiving phase;RP) located in the lumen of the hollow fiber. The effects of several factors such as the nature of organic solvent, compositions of SP and RP solutions, extraction time, ionic strength and stirring rate on the extraction efficiency were examined and optimized. An enrichment factor of 360 along with substantial sample clean up was obtained under the optimized conditions. The calibration curve showed linearity in the range of 1 - 500 ng?mL–1 and the limit of detection was found to be 0.5 ng?mL–1 in aqueous medium. A reasonable relative recovery (≥89%) and satisfactory intra-assay (3.7% - 4.2%, n = 3) and inter-assay (7.5% - 7.8%, n = 3) precision illustrated good performance of the analytical procedure in spiked human urine and plasma samples.展开更多
A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmet...A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmetic products. A canular extractor was assembled by mounting a hollow fiber inside an external tube with a tee-connector. The organic solvent was immobilized into the fiber to form a liquid membrane as the acceptor phase. The sample was continuously injected into the extractor and the UV filters were extracted from the aqueous sample into organic acceptor phase. The main parameters affecting HF-LPME including extraction solvent, sample volume, sample flow rate, pH values and ionic strength were investigated. Toluene has been verified to be suitable as the acceptor phase. Under the optimized HF-LPME conditions, the enrichment factors of five UV filters varying from 24 to 57 were achieved. The limits of detection for the five UV filters were in the range of 1-100 μg L-1 .The relative standard deviations (RSDs) of HF-LPME and HPLC analysis were lower than 5.2%. The proposed method has been successfully applied to the analysis of the varied cosmetic products.展开更多
文摘The applicability of hollow fiber liquid-phase microextraction (HF-LPME) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was evaluated for the extraction and determination of tamoxifen (TAM) in biological fluids including human urine and plasma. The drug was extracted from a 15 mL aqueous sample (source phase;SP) into an organic phase impregnated in the pores of the hollow fiber (membrane phase;MP) followed by the back-extraction into a second aqueous solution (receiving phase;RP) located in the lumen of the hollow fiber. The effects of several factors such as the nature of organic solvent, compositions of SP and RP solutions, extraction time, ionic strength and stirring rate on the extraction efficiency were examined and optimized. An enrichment factor of 360 along with substantial sample clean up was obtained under the optimized conditions. The calibration curve showed linearity in the range of 1 - 500 ng?mL–1 and the limit of detection was found to be 0.5 ng?mL–1 in aqueous medium. A reasonable relative recovery (≥89%) and satisfactory intra-assay (3.7% - 4.2%, n = 3) and inter-assay (7.5% - 7.8%, n = 3) precision illustrated good performance of the analytical procedure in spiked human urine and plasma samples.
基金supported by the National Natural Science Foundation of China (90813015 & 20935002)
文摘A simple method based on hollow fiber liquid-phase microextraction (HF-LPME) followed by high performance liquid chro-matography (HPLC) analysis was successfully developed for the determination of UV filters in cosmetic products. A canular extractor was assembled by mounting a hollow fiber inside an external tube with a tee-connector. The organic solvent was immobilized into the fiber to form a liquid membrane as the acceptor phase. The sample was continuously injected into the extractor and the UV filters were extracted from the aqueous sample into organic acceptor phase. The main parameters affecting HF-LPME including extraction solvent, sample volume, sample flow rate, pH values and ionic strength were investigated. Toluene has been verified to be suitable as the acceptor phase. Under the optimized HF-LPME conditions, the enrichment factors of five UV filters varying from 24 to 57 were achieved. The limits of detection for the five UV filters were in the range of 1-100 μg L-1 .The relative standard deviations (RSDs) of HF-LPME and HPLC analysis were lower than 5.2%. The proposed method has been successfully applied to the analysis of the varied cosmetic products.
