Μicrodisk Αrray for the microextraction of non-steroidal anti-inflammatory drugs from human urine coupled with HPLC-UV analysis

A hydrophobic microdisk array (MDA) was fabricated and applied for the selective microextraction of certain non-steroidal anti-inflammatory drugs (NSAIDs) from human urine. The MDA device consisted of two C18 microdisks which were concentrically adjusted to a stainless-steel spinal needle with the aid of frit-based stoppers. The principle of the method is based on the immersion of the MDA device in 1500 μL of aqueous sample for 27 min for analyte adsorption. After cleaning with water, the array was immersed into 500 μL of methanol for analytes' desorption and analyzed by HPLC-UV. The critical parameters influencing the adsorption and elution performance of the MDA procedure were thoroughly investigated and optimized using a multivariate analysis. Adsorption experiments were conducted to estimate the adsorption capacity of the sorbent. Under optimized conditions the method was linear in the range of 50–3000 ng/mL with LODs ranged between 9 and 65 ng/mL. The precision of the method (intra-day and inter-day) was less than 12.1 % while the accuracy (expressed as relative recoveries) was between 89.5 and 106.4 %. It was found that the MDA device can be reused up to 20 consecutive extractions while the greenness of the method was assessed through the AGREEprep indexes. While sensitivity was slightly lower than advanced microextraction techniques, the MDA offers advantages in simplicity, reusability, and sustainability. The applicability of the developed analytical scheme was demonstrated by analyzing real urine samples after oral administration of ketoprofen-containing pharmaceutical formulations. • The new Microdisk array (MDA) microextraction is presented. • Hydrophobic disks were utilized as sorptive materials. • The MDA can be reused up to 20 consecutive extractions. • A rapid protocol was proposed for the determination of urinary NSAIDs.