Establishment of the new dispersive solid phase microextraction method with green adsorbent CaAl-LDH hybrid with g-C 3 N 4 utilised for the determination of Pb 2+ in Instant cup noodles and environmental samples

Abstract

Adsorbents with a significant adsorption capacity and high selectivity are required to identify and eliminate heavy metal ions from the under study environmental and food samples. For this purpose, in the present work a new adsorbent, graphitic carbon nitride g-C3N4 hybrid with CaAl layered double hydroxide was effectively synthesised using an easy hydrothermal co-precipitation procedure and applied for Pb2+ determination in food and water samples using dispersive solid phase-microextraction (DSP-µE) via FAAS. The as synthesized CaAl-LDH@g-C3N4 nanocomposites characteristic were examined using XRD, SEM, SEM-EDX and FTIR. Significant analytical parameters were optimised such as pH 8, adsorbent quantity 10 mg, and adsorption and elution times 30 and 60 sec, respectively. Additionally, a sample volume of 20 mL and eluent volume of 2 mL were used with an elution solvent of 0.5 M HNO3. Matrix effect was also performed as verification of the developed method. Limit of detection (LOD) value 0.54 µg/L, limit of quantification (LOQ) value 1.79 µg/L, enrichment factor (EF) 10.69 and preconcentration factor (PF) 10, was determined. The %RSD < 10% with R2 of 0.999 has proven the linearity and high accuracy of the developed method. ComplexMoGAPI evaluation (score 79) confirmed the excellent greenness of the proposed method. Standard reference materials (SRMs) were used to affirm the accuracy of the method. Different instant noodles samples, and tap water samples were analysed for their Pb2+ content, allowing for successful determination of Pb2+ contents in them.