Determination of naproxen in serum by capillary electrophoresis with ultraviolet absorbance and laser-induced fluorescence detection

✍ Scribed by Helena Soini; Milos V. Novotny; Marja-Liisa Riekkola

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 478 KB
• Volume: 4
• Category: Article
• ISSN: 1040-7685
• DOI: 10.1002/mcs.1220040404

✦ Synopsis

Abstract

Methodology for quantitative determination of an anti‐inflammatory drug, naproxen, in human serum by capillary electrophoresis (CE) is described. Ultraviolet absorbance (UV) and laser‐induced fluorescence (LIF) detection without derivatization procedures have been applied in two concentration ranges: the UV absorbance detection method is applicable in the concentration range of 0.5 ‐ 25 μg mL^−1^ (2 μM – 100 μM), permitting pharmacokinetic studies after a single oral dose of naproxen; for the lower concentration range of 0.01 – 0.5 μg mL^−1^ (40 nM ‐ 2 μM), LIF detection has been utilized. Sample preparation includes a simple liquid‐liquid extraction of 1.0 mL (UV) or 0.25 mL (LIF) serum aliquots. After solvent evaporation, redissolved samples were analyzed using Tris‐Tricine buffer. UV absorbance measurement was set at 254 nm. LIF using the helium‐cadmium (He‐Cd) laser as a source (excitation at 325 nm) was measured at 375 nm due to the native fluorescence of naproxen. Both methods provided interference‐free, linear and highly precise results. At the quantitation limit, 0.1‐pmol (UV) and 3‐fmol (LIF) naproxen levels were detected. Using ketoprofen (UV) and warfarin (LIF) as internal standards, analytical precision improved substantially.