Determination of Mesalamine by Spectrofluorometry in Human Serum after Solid-Phase Extraction with Ni-Al Layered Double Hydroxide as a Nanosorbent

Nanostructured nickel-aluminum layered double hydroxide (Ni-Al LDH) was synthesized and the potential of the obtained material, as solid-phase extraction (SPE) sorbent, for separation and pre-concentration of trace amount of mesalamine (5-aminosalicylic acid) was assessed using column method. The retained analyte on Ni-Al LDH was eluted with NaOH solution and the concentration of the elueted 5-ASA was then spectrofluorometrically determined at lambda(em) = 480 nm with excitation at lambda(ex) = 340 nm. Various experimental parameters affecting the extraction efficiency of mesalamine on Ni-Al (NO3-) LDH, such as pH, amount of sorbent, sample loading flow rate, elution conditions and sample volume, were investigated. In the optimum experimental conditions, the limit of detection and enrichment factor were 0.04 and 40 mu g L-1, respectively. The calibration graph for the pre-concentration system was linear in the range of 0.1-45.0 mu g L (1) with a correlation coefficient of 0.998. The relative standard deviation (RSD) resulting from the analysis of six replicates of 100 mL solutions containing 1.0 mu g L-1 mesalamine was 2.05%. The optimized method was successfully applied to the determination of mesalamine in blood serum samples.