Determination of Ni and Zn in an Oil Matrix using Schiff Base‐Assisted Extraction Followed by a Flame Atomic Absorption Spectrometer: A Simple Strategy to Determine Ni and Zn

Abstract

In the present work, a new and simple Schiff base‐assisted extraction strategy for Ni and Zn from an edible oil matrix with subsequent determination using a flame atomic absorption spectrometer was suggested. According to the green approach, laborious sample‐pretreatment procedures were eliminated via complexation of the analytes with N,N′‐bis(4‐methoxysalycylidene)‐2‐hydroxy‐1,3‐propanediamine (4MSHP) and transferred from the oil phase to the aqueous phase. The complexation properties of 4MSHP, Ni, and Zn were investigated using UV–vis spectrophotometry. The experimental conditions that affect the extraction efficiency were optimized using central composite design. The optimum conditions for the extraction of Ni and Zn were as follows: a volume to oil mass ratio of 0.83 to 1.31 mL g−1 of 4MSHP solution; 62.3‐ and 50.6‐min, stirring time; 27.3 and 31.1 °C, temperature, respectively. The detection limits (3sbm−1) were 0.41 μg g−1 for Ni and 0.16 μg g−1 for Zn. Validation of the suggested work was performed by the analysis of organometallic standard‐doped n‐hexane solutions as certified reference materials under the optimum experimental conditions. The recovery percentages were warranted the accuracy and found as 98.2 ± 1.8% for Ni and 99.8 ± 1.2% for Zn. In addition, relative SD values were below 5% for both the analytes. The Student's t‐test showed that there was no significant difference between the found and doped amount of analytes at 95% confidence level. The features such as the detection technique, cheapness, eco‐friendly solvent usage, and practicality were better compared to the literature.