Humans may be exposed to toxic elements such as Ni(II) mainly from consumption of food and drinking water. Considering the importance of olive oil in Mediterranean diet, ensuring the quality and safety of olive oils is essential for their shelf life, food industry and public health [1]. Herein, assessment of Ni(II) contents of different olive oil samples that obtained from local markets of Balıkesir/Türkiye, were carried out.
Additionally, a novel solid phase extraction method was used for preconcentration before determination [2]. The sorbent was synthesized and modified for the aim of Ni(II) sorption. Experimentally, the transfer of the analyte ion to the aqueous phase was achieved using a solid phase extraction based methodology with a greenness score of 0.51 that does not require decomposition of oil matrix.
The approach involves mixing 19.1 mL of oil sample with 0.22 g of magnetically characterized solid sorbent for 58.3 s in sorption step. After separation of the sorbent with an external magnet, elution of the analytes were achieved vortexing with 6 mL of 0.86 mol L-1 HNO3 solution for 95 s. Finally, eluents were separated using the external magnet and subjected to the detection. A flame atomic absorption spectrometry (FAAS) was utilized for the quantification of Ni(II) content of the eluents equipped with a hallow cathode lamp. As the method was specifically developed for the separation and preconcentration of Ni(II) in oil matrix, the instrumental quantification limit did not constitute a limiting factor for its accurate determination. The obtained Ni(II) contents of olive oils were used for calculation of chronic daily intake (CDI), target hazard quotient (THQ) and carcinogenic risk (CR) for assessing the health risks of the analyte.