On‐chip electromembrane extraction of acidic drugs

• Published in: Electrophoresis Vol. 40; no. 18-19; pp. 2514 - 2521
• Main Authors: Roman‐Hidalgo, Cristina, Santigosa‐Murillo, Elia, Ramos‐Payán, María, Petersen, Nickolaj J., Kutter, Jörg P., Pedersen‐Bjergaard, Stig
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.09.2019
• Subjects: Acid drugs; Analytical chemistry; Chromatography, High Pressure Liquid; Diclofenac; Drugs; Dynamic stability; Electromembrane extraction; Electrophoresis, Microchip; Equipment Design; Female; Humans; Hydrogen-Ion Concentration; Ibuprofen; Ketoprofen; Limit of Detection; Linear Models; Liquid membrane extraction; Liquid membranes; Male; Membranes, Artificial; Microchip; Microfluidic Analytical Techniques - instrumentation; Naproxen; Pharmaceutical Preparations - chemistry; Pharmaceutical Preparations - isolation & purification; Pharmaceutical Preparations - urine; Polymethyl methacrylate; Reproducibility of Results; Salicylic acid; Stability analysis; Urine; Urine samples; Electromembrane extraction; Acid drugs; Urine samples; Microchip
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/elps.201900024

In the present work, a new supported liquid membrane (SLM) has been developed for on‐chip electromembrane extraction of acidic drugs combined with HPLC or CE, providing significantly higher stability than those reported up to date. The target analytes are five widely used non‐steroidal anti‐inflammatory drugs (NSAIDs): ibuprofen (IBU), diclofenac (DIC), naproxen (NAX), ketoprofen (KTP) and salicylic acid (SAL). Two different microchip devices were used, both consisted basically of two poly(methyl methacrylate) (PMMA) plates with individual channels for acceptor and sample solutions, respectively, and a 25 µm thick porous polypropylene membrane impregnated with the organic solvent in between. The SLM consisting of a mixture of 1‐undecanol and 2‐nitrophenyl octyl ether (NPOE) in a ratio 1:3 was found to be the most suitable liquid membrane for the extraction of these acidic drugs under dynamic conditions. It showed a long‐term stability of at least 8 hours, a low system current around 20 µA, and recoveries over 94% for the target analytes. NPOE was included in the SLM to significantly decrease the extraction current compared to pure 1‐undecanol, while the extraction properties was almost unaffected. Moreover, it has been successfully applied to the determination of the target analytes in human urine samples, providing high extraction efficiency.