Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop with Central Composite Design for the Spectrofluorometric Determination of Naproxen.

A quick, simple and efficient method for extraction, preconcentration, and determination of naproxen in water and plasma specimens with acceptable recovery by dispersive liquid-liquid microextraction based on solidified floating organic drop with spectrofluorimetry is presented. Various parameters affecting the extraction efficiency are optimized by the Central Composite Design. Moreover, under optimal conditions (120 µL 1-Undecanol with 1 mL Ethanol, pH = 3.5, 2 mL KCl 10% solution), the calibration curve was linear in the range 10.0-120.0 ng/mL. Finally, for naproxen, the detection limit was 2.4 ng/mL.

Carbon Dots Green Synthesis for Ultra-Trace Determination of Ceftriaxone Using Response Surface Methodology.

The present study sought to develop a facile and green synthetic approach for producing fluorescent carbon dots (CDs) from a natural biomass using aqueous extraction of carbonized blue crab shell. Spherical carbon dots (6.00 ± 3.0 nm) exhibited an extended emission range with excellent quantum yield (14.5 ± 3.5%). In order to measure ceftriaxone, we offered a simple and sensitive method, based on fluorescence quenching of carbon dots in plasma and water with recovery values of 94.5-104.1%. Furthermore, with usage of central composite design (CCD) based response surface methodology (RSM); we optimized the effect of different factors. In addition, ANOVA evaluated the accuracy and suitability of quadratic model. Under optimal conditions, fluorescence quenching revealed a sensitive response in the concentration range of 20-1000 nM with the limit of detection 9.0 nM for ceftriaxone. Finally, carbon dots-based fluorescence quenching procedure was able to quantify ceftriaxone in plasma, as well as mineral and tap water. Spiked samples achieved satisfactory efficiencies.