Optimized miniaturized air-assisted liquid–liquid microextraction for determination of non-steroidal anti-inflammatory drugs in bio-fluid samples

Abstract

A miniaturized air-assisted liquid–liquid microextraction (M-AALLM) method was developed for the simultaneous extraction of amlodipine (Am), atorvastatin (At), and ibuprofen (Ib) in some human bio-fluid samples prior to their determination using high performance liquid chromatography (HPLC). Since all steps are performed in a capillary tube, not only is there no need to use a disperser solvent, and the volumes of the extraction solvent and the sample solution are less than those in the other liquid-phase microextraction methods, but also a much better dispersion occurs. Several significant parameters including the type and volume of the extraction solvent, pH and ionic strength of the sample solution, and number of extraction cycles were investigated and optimized using a central composite design (CCD) strategy. The optimal extraction efficiencies were achieved using 2.6 μL of n-octanol, 50 μL of the sample solution including 3.25 g mL⁻¹ of NaCl, and 4 extraction cycles (∼20 s). The limits of detection, linear dynamic ranges (with r² > 0.99), recoveries, and repeatabilities were obtained to be 3 ng mL⁻¹, 0.01–235 μg mL⁻¹, 92–95%, <4.7% (intra-day precision), and <5.9% (inter-day precision), respectively. The results obtained indicate that the proposed M-AALLME method has desirable merits to apply as a simple and fast method for simultaneous determination of the tested drugs in the human plasma and urine samples.