DOI: https://doi.org/10.55373/mjchem.v26i5.614

Keywords: Dispersive micro solid phase extraction; graphene oxide; hydrocortisone; water samples; liquid chromatography

Abstract

Hydrocortisone (HYD) is a synthetic corticosteroid widely used as an anti-inflammatory in human and veterinary medicine. Its presence in environmental water, though in trace concentration, is evident in posing hazardous risks towards aquatic organisms, which leads to numerous health and environmental issues. This contaminant enters environmental water through improper disposal of expired drugs, production residues, and spillage during manufacturing. Dispersive micro-solid phase extraction (D-µSPE) is a solid-phase extraction technique capable of enhancing reproducibility when dealing with low-concentration samples and is excellent in eliminating interferences. In this study, D-µSPE was developed and optimised using graphene oxide (GO) as sorbent coupled with high-performance liquid chromatography (HPLC) to pre-concentrate HYD in water samples. Several parameters, such as sorbent mass, sample pH, extraction time and solvent desorption volume, were investigated using a time (OFAT) approach followed by Liquid Chromatography analysis. Under the optimum conditions, the method provided a good linearity of 0.9882 over a concentration range of 50 and 400 μg L-1. The limit of detection (LOD) and limit of quantification (LOQ) values were 2.77 μg L-1 and 8.38 μg L-1, respectively. The relative recovery was calculated within the range of 98 – 120%, and an excellent relative standard deviation (RSD) of ≤ 5% (n = 3) was obtained. The D-μ-SPE-GO method was successfully applied to tap water samples. The results showed that the developed method was selective, sensitive, and environmentally friendly to the water samples.