Repurposing eggshell membrane, a natural food waste, for in-syringe membrane solid phase extraction: Mercury determination in water samples

Abstract

A rapid, simple, and cost-effective method for the determination of mercury in water samples using an eggshell membrane (ESM) as a sorbent material in the in-syringe membrane solid-phase extraction (ISMSPE) technique has been developed. The utilization of ESM, a natural waste product and a cost-effective sorbent material for ISMSPE, presents a promising approach for the determination of mercury ions, Hg(II), in water samples prior to cold vapor AAS (CV-AAS) analysis. The selectivity study of ESM shows that ESM's adsorption performance for Hg(II) is the highest among other metals, by 44.2%. The optimization for Hg(II) preconcentration, which includes the choice of eluting reagent, concentration, and volume of the eluting reagent, the number of cycles of adsorption and desorption, and sample volume, is discussed in this study. The range of linearity of this method was 0.5–100 μg/L, with a preconcentration factor of 80. This method exhibited good sensitivity, with an LOD and LOQ of 0.44 μg/L and 1.32 μg/L, respectively. The precision and accuracy of the method were also satisfactory, as indicated by the recoveries for three real water samples in the range of 89.3–99.7% and RSD% (n = 3), ranging from 1.0 to 8.0%. These findings demonstrate that the developed method is reliable and performs well in determining Hg(II) ions in real water samples. This study has successfully demonstrated ESM's potential as a valuable material for the preconcentration of Hg(II), offering an environmentally friendly approach that promotes sustainability.