Study of the solid-phase extraction of diclofenac sodium, indomethacin and phenylbutazone for their analysis in human urine by liquid chromatography.
A selective semi-automated solid-phase extraction (SPE) of the non-steroidal anti-inflammatory drugs diclofenac sodium, indomethacin and phenylbutazone from urine prior to high-performance liquid chromatography was investigated. The drugs were recovered from urine buffered at pH 5.0 using C18 Bond-Elut cartridges as solid sorbent material and mixtures of methanol-aqueous buffer or acetonitrile-aqueous buffer as washing and elution solvents. The extracts were chromatographed on a reversed-phase ODS column using 10 mM acetate buffer (pH 4.0)-acetonitrile (58:42, v/v) as the mobile phase, and the effluent from the column was monitored at 210 nm with ultraviolet detection. Absolute recoveries of the anti-inflammatory drugs within the range 0.02-1.0 microg/ml were about 85% for diclofenac and indomethacin, and 50% for phenylbutazone without any interference from endogenous compounds of the urine. The within-day and between-day repeatabilities were in all cases less than 5% and 10%, respectively. Limits of detection were 0.007 microg/ml for diclofenac sodium and indomethacin and 0.035 microg/ml for phenylbutazone, whereas limits of quantitation were 0.02 microg/ml for diclofenac and indomethacin and 0.1 microg/ml for phenylbutazone.
Department of Analytical Chemistry, Faculty of Sciences, University of the Basque Country, Bilbao, Spain.
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A
Bakkali
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Corta
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LA
Berrueta
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B
Gallo
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Vicente
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004008:Diclofenac / Q000652:urine*; D006801:Humans; D007213:Indomethacin / Q000652:urine*; D010653:Phenylbutazone / Q000652:urine*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
D000894:Anti-Inflammatory Agents, Non-Steroidal; D004008:Diclofenac; D010653:Phenylbutazone; D007213:Indomethacin