Novel Salicylic Acid Modified Magnetic Nanoparticles Based Ligandless Extraction for the Accurate Determination of Bismuth in Urine Samples by Flame Atomic Absorption Spectrophotometry

An efficient, novel, rapid and green ligandless dispersive solid phase extraction method (LDSPE) based on salicylic acid modified magnetic iron nanoparticles (SA-MNPs) was combined with slotted quartz tube integrated flame atomic absorption spectrometry (SQT-FAAS) for sensitive bismuth determination in human urine. For this purpose, SA-MNPs were synthesized via a simple procedure and used as sorbent for the effective extraction/preconcentration of bismuth from the aqueous samples. This is the first report in the literature in which this analytical combination (SA-MNPs-LDSPE-SQT-FAAS) was utilized for the determination of bismuth. Under the determined optimum conditions, the linear range was between 20 and 250 µg L⁻¹. The limit of detection (LOD) and limit of quantification (LOQ) values for bismuth were 6.0 and 21.0 µg L⁻¹, respectively. A 94-fold enhancement in the detection power of FAAS was achieved using the SA-MNPs-LDSPE-SQT-FAAS method. To examine the method’s accuracy and applicability, the optimal procedure was applied to spiked human urine. Satisfactory recoveries from 95% to 101% were obtained with matrix matching, indicating that the developed method can be used for bismuth determination in biological samples.