Determination of non-steroidal anti-inflammatory drugs in urine by the combination of stir membrane liquid–liquid–liquid microextraction and liquid chromatography

• Published in: Analytical and bioanalytical chemistry 2012-07, Vol.403 (9), p.2583-2589
• Main Authors: Riaño, S., Alcudia-León, M. C., Lucena, R., Cárdenas, S., Valcárcel, M.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Anti-Inflammatory Agents, Non-Steroidal - isolation & purification; Anti-Inflammatory Agents, Non-Steroidal - urine; Biochemistry; Characterization and Evaluation of Materials; Chemical properties; Chemistry; Chemistry and Materials Science; Chromatography, Liquid - methods; Composition; Drugs; Extraction; Extraction (Chemistry); Flurbiprofen - isolation & purification; Flurbiprofen - urine; Food Science; Humans; Identification and classification; Indomethacin - isolation & purification; Indomethacin - urine; Ketoprofen - isolation & purification; Ketoprofen - urine; Laboratory Medicine; Limit of Detection; Liquid chromatography; Liquid Phase Microextraction - methods; Mathematical analysis; Membranes; Methods; Monitoring/Environmental Analysis; Naproxen; Naproxen - isolation & purification; Naproxen - urine; Nonsteroidal anti-inflammatory drugs; Stirring; Technical Note; Urine
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-012-6051-2

A stir membrane liquid phase microextraction procedure working under the three-phase mode is proposed for the first time for the determination of six anti-inflammatory drugs in human urine. The target compounds are isolated and preconcentrated using a special device that integrates the extractant and the stirring element. An alkaline aqueous solution is used as extractant phase while 1-octanol is selected as supported liquid membrane solvent. After the extraction, all the analytes are determined by liquid chromatography (LC) with ultraviolet detection (UV). The analytical method is optimized considering the main involved variables (e.g., pH of donor and acceptor phases, extraction time, stirring rate) and the results indicate that the determination of anti-inflammatory drugs at therapeutic and toxic levels is completely feasible. The limits of detection are in the range from 12.6 (indomethacin) to 30.7 μg/L (naproxen). The repeatability of the method, expressed as relative standard deviation (RSD, n  = 5) varies between 3.4 % (flurbiprofen) and 5.7 % (ketoprofen), while the enrichment factors are in the range from 35.0 (naproxen) to 72.5 (indomethacin).