Peristaltic Pump Assisted Zirconium Nanoparticles based Pipette-tip Solid Phase Extraction for the Determination of Cobalt by Slotted Quartz Tube-Flame Atomic Absorption Spectrophotometry
In this work, a novel, efficient, simple and green solid phase extraction (SPE) method based on a pipette-tip filled with zirconium nanoparticles (Zr-NPs) was developed for the sensitive determination of cobalt by slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS) in soil samples. Zirconium nanoparticles provided repeatable and reproducible signals of the analyte were synthesized with a practical method and used as an adsorbent. Extraction and preconcentration steps were performed in a customized pipette-tip loaded with zirconium nanoparticles. All parameters having significant effects on the analyte signal (pH and volume of buffer, amount of nanoparticles, type, concentration and volume of eluent, sample volume and sample flow rate) and instrumental conditions were optimized to obtain the best experimental outcomes. Under the optimum conditions, linear range of the developed method was found to be between 7.5-75 µg/L with a correlation coefficient of 0,9998. SPE method offered a 56-fold enhancement in the detection power of the FAAS with the limits of detection and quantification (LOD/LOQ) values calculated as 2.2 and 7.2 µg/L, respectively. Developed method was applied to soil samples in order to test both its applicability and accuracy for real sample applications. Percent recoveries obtained were in the range of 90-101% which represents the method’s accuracy and applicability in complex matrices like soil samples.