title: Optimization of microwave-assisted extraction of analgesic and anti-inflammatory drugs from human plasma and urine using response surface experimental designs.
abstract: The performance of microwave-assisted extraction and HPLC with photodiode array detection method for determination of six analgesic and anti-inflammatory drugs from plasma and urine, is described, optimized, and validated. Several parameters affecting the extraction technique were optimized using experimental designs. A four-factor (temperature, phosphate buffer pH 4.0 volume, extraction solvent volume, and time) hybrid experimental design was used for extraction optimization in plasma, and three-factor (temperature, extraction solvent volume, and time) Doehlert design was chosen to extraction optimization in urine. The use of desirability functions revealed the optimal extraction conditions as follows: 67°C, 4 mL phosphate buffer pH 4.0, 12 mL of ethyl acetate and 9 min, for plasma and the same volume of buffer and ethyl acetate, 115°C and 4 min for urine. Limits of detection ranged from 4 to 45 ng/mL in plasma and from 8 to 85 ng/mL in urine. The reproducibility evaluated at two concentration levels was less than 6.5% for both specimens. The recoveries were from 89 to 99% for plasma and from 83 to 99% for urine. The proposed method was successfully applied in plasma and urine samples obtained from analgesic users.
authors.affiliation: Institute of Legal Medicine, Forensic Toxicology Service, Faculty of Medicine, Santiago de Compostela, Spain.
authors.forename: Purificación
authors.initials: P
authors.lastname: Fernández
authors.forename: Ana M
authors.initials: AM
authors.lastname: Fernández
authors.forename: Ana M
authors.initials: AM
authors.lastname: Bermejo
authors.forename: Rosa A
authors.initials: RA
authors.lastname: Lorenzo
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Carro
mesh_terms: D000700:Analgesics / Q000097:blood / Q000302:isolation & purification* / Q000652:urine; D000893:Anti-Inflammatory Agents / Q000097:blood / Q000302:isolation & purification* / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008872:Microwaves; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
chemical_list: D000700:Analgesics; D000893:Anti-Inflammatory Agents