title: A dispersive liquid-liquid microextraction method based on the solidification of a floating organic drop combined with HPLC for the determination of lovastatin and simvastatin in rat urine.
abstract: A dispersive liquid-liquid microextraction method based on solidification of floating organic drop combined with HPLC was developed for the determination of lovastatin and simvastatin in rat urine for the first time. 1-Dodecanol and methanol were used as the extraction and disperser solvents, respectively. Several important parameters influencing the micro-extraction efficiency were studied and systematically optimized, including the type and volume of extraction solvent and disperser solvent, extraction time, pH and salt concentration. The analytes were separated on a Kromasil C18 column at 30°C with a mobile phase of methanol and 0.2% acetic acid in water (83:17, v/v) and detected at 238 nm. Under the optimal conditions, the maximum number of enrichment factors for both analytes was 27. The linear ranges were 20.08-1004 and 20.00-1000 µg/L with the correlation coefficients ranging from 0.9990 to 0.9994 for lovastatin and simvastatin, respectively. The volume of organic solvent consumed in extraction was <0.3 mL, and the extraction time was 10 min. The newly developed environment-friendly sample pretreatment method will be a good alternative to conventional techniques, such as solid-phase extraction, liquid-liquid extraction and protein precipitation, for the HPLC determination of lovastatin and simvastatin in biological samples.
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 110016, China.
authors.forename: Longshan
authors.initials: L
authors.lastname: Zhao
authors.forename: Pan
authors.initials: P
authors.lastname: Zhao
authors.forename: Linli
authors.initials: L
authors.lastname: Wang
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Ma
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Hou
authors.forename: Famei
authors.initials: F
authors.lastname: Li
mesh_terms: D000818:Animals; D000924:Anticholesteremic Agents / Q000302:isolation & purification* / Q000652:urine*; D002851:Chromatography, High Pressure Liquid; D059627:Liquid Phase Microextraction / Q000379:methods*; D008148:Lovastatin / Q000302:isolation & purification* / Q000652:urine*; D051381:Rats; D019821:Simvastatin / Q000302:isolation & purification* / Q000652:urine*
chemical_list: D000924:Anticholesteremic Agents; D008148:Lovastatin; D019821:Simvastatin
keywords: HPLC; dispersive liquid-liquid micro-extraction based on solidification of floating organic drop; lovastatin; rat urine; simvastatin