Spray assisted preconcentration method combined with HPLC – Continuous flow hydride generation – FAAS for inorganic arsenic speciation in olive oil samples

Abstract

Speciation analysis of arsenic in edible oils is an important topic in terms of the assessment of its risks for human health and the quality of edible oils. In this study, high performance liquid chromatography – continuous flow hydride generation – flame atomic absorption spectrometry (HPLC-CFHG-FAAS) system after vortex assisted reverse phase spray-based fine droplet formation liquid phase microextraction (VA-RP-SFDF-LPME) method was proposed to qualify/quantify arsenite and total arsenic. Limit of detection (LOD) and limit of quantification (LOQ) for arsenite were calculated as 2.86 µg kg–1 (as As) and 9.52 µg kg–1 (as As), respectively. After the extraction/preconcentration process, a prereduction was carried out in the presence of 0.010 mol/L HCl (containing 0.39% L-cysteine) with heat (90 ± 5 oC) for the determination of total arsenic content while arsenite was directly determined via the developed system. Recovery for arsenite and total inorganic arsenic were in the range of 91.5 – 120.4% and 90.0 – 104.4%, respectively. The developed method is proposed for the analysis of olive oil samples containing inorganic arsenic species. This is the first study to carry out the inorganic arsenic speciation in olive oil by HPLC-CFHG-FAAS system after the preconcentration of the species by the VA-RP-SFDF-LPME system. For the matrix including arsenite and arsenate, the developed method can be safely used to find the concentration of both species accurately.