Functionalized nanodiamonds with NiCoFe layered double hydroxides used as a novel adsorbent in dispersive solid phase microextraction for Pb(II) determination in juice samples

[Display omitted] •Preparation of a novel adsorbent functionalized nanodiamonds with NiCoFe-LDH, by using the hydrothermal method.•Nanodiamonds@NiCoFe-LDH has been used for the dispersive solid-phase microextraction for lead Pb(II).•Pb(II) was investigated at low LOD levels via FAAS, without any foreign ions interfering.•The developed method was found effective with low sample volume and low adsorbent amount.•The method was successfully applied to commercial juice samples of different brands. A new solid phase microextraction (SPME) method utilizing nanodiamonds@NiCoFe-LDH for the pretreatment and extraction of Pb(II) before sample determination through FAAS was developed. NiCoFe-LDH was synthesized by using a hydrothermal synthesis technique and then combined with functionalized nanodiamonds. For the characterization of nanodiamonds@NiCoFe-LDH composite, FT-IR, FE-SEM, and XRD were utilized. The analytical parameters (pH level, amount of sorbent, concentration of eluent, volumes of sample and eluent, desorption time), i.e., pH = 8.0, 5.0 mg, 0.5 mol/L, 50 mL, 1.5 mL, and 0.5 min, respectively, were studied to set the maximum efficiency of the developed method. Additionally, matrix effects were taken into consideration during the evaluation process using the standard addition method. The limit of detection (LOD) and the preconcentration factor (PF) were obtained as 0.62 ng mL-1 and 25, respectively. To confirm the accuracy of the newly developed method, certified reference materials (CRMs) (NIST SRM 1515 apple leaves and BCR-505 estuarine water) were employed. %RSD was calculated as 2.0–8.0. The optimized method was successfully implemented to quantify Pb(II) in commercially available fruit juices of various brands and flavors procured from local markets in Kayseri, Turkey. Compared to previously reported methods, the developed method demonstrated exceptional sensitivity, achieving a remarkably low LOD.