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The widespread use and misuse of antibiotics in pharmaceuticals and animal farming has resulted in their accumulation in food sources and the environment, posing significant threats to human health, the environment, and the global economy. In this study, we have developed a hypersensitive, and ultra-selective electrochemical sensor, the first of its kind, by integrating a thermally annealed gold-silver alloy nanoporous matrix (TA-Au-Ag-ANpM) with reduced graphene oxide (r-GO) and poly(glycine) at the surface of a glassy carbon electrode (GCE). This sensor aims to detect life-threatening metronidazole (MTZ) residues in food samples. TA-Au-Ag-ANpM/r-GO/poly(glycine)/GCE was thoroughly characterized using a range of analytical techniques, including UV-Vis, FT-IR, XRD, SEM, and EDX. Furthermore, its electrochemical properties were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). The sensor exhibited outstanding performance, with a broad linear range of 2.0 pM-410 μM. The limits of detection (LOD) and quantification (LOQ) were determined to be 0.0312 pM and 0.104 pM, respectively. The TA-Au-Ag-ANpM/r-GO/poly(glycine)/GCE exhibited exceptional reproducibility, repeatability, stability, and resistance to interferences. Moreover, the sensor demonstrated outstanding performance in detecting MTZ residues in milk powder, pork, and chicken meat samples, achieving very good recoveries (96.9%-101.4%) with a relative standard deviation (RSD) below 5%. This performance highlights the potential for practical applications in food safety and quality monitoring. Therefore, the developed sensor contributes to the advancement of electrochemical sensing technology and its application in ensuring food safety and integrity by combating antibiotic residues., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study aimed to assess the concentrations of major and trace metals (Na, Ca, Fe, Zn, Ni, Mn, Cu, Cd, and Pb) in date palm fruit samples collected from diverse regions, including Afar (Ethiopia), Iraq, and Saudi Arabia, utilizing flame atomic absorption spectrometry (FAAS). The wet acid digestion method was employed for sample treatment, with optimization of the key parameters such as reagent volume ratio, oven temperature, and digestion time for analytical applications. Under the optimized parameters, average metal concentrations in date palm fruit samples ranged from 205-299, 134-320, 38.8-115, 25.1-42.2, 9.27-27.9, 7.11-16.3, and 0.002-1.15 mg/kg for Ca, Na, Fe, Ni, Zn, Mn, and Cu, respectively. Cd and Pb levels were below detection limits within the linear range. Generally, date palm samples exhibited higher Ca and Na contents and lower concentrations of Cu and Mn than other metals. Pearson correlation analysis revealed very strong positive correlations between Fe and Na, Na and Zn, Na and Mn, Ca and Zn, Fe and Ni, Fe and Mn, and Mn and Ni. Strong negative correlations were observed for Ni and Na, Fe and Cu, and Cu and Ni. Weak correlations were noted among Na and Cu, Ca and Fe, Ca and Ni, Ca and Mn, Ca and Cu, Fe and Zn, Ni and Zn, Zn and Mn, and Zn and Cu. A recovery study using the spiking method demonstrated acceptable percentage recoveries ranging from 91.6% to 97.8%. Health risk assessment, including chronic daily intake (CDI), hazard quotient (HQ), total exposure hazard index (HI), and carcinogenic risk (CR), indicated CDI, HQ, and HI values below 1.0, except for the HI value for Ni. This suggests that the metals pose no probable public health risk, with the absence of Cd and Pb in date palm samples affirming no carcinogenic threats associated with their consumption., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2024 Feven Tamirat et al.)

In this study, for the first time, the levels of thirteen micro- and macromineral nutrients in the leaves, seeds, and supportive soil of Moringa stenopetala ( M. stenopetala ) were simultaneously determined using microwave plasma atomic emission spectroscopy (MP-AES). The samples were collected during the arid season, in 2019 from the three main M. stenopetala growing areas in southern Ethiopia (Chano Mile Kebele, Nechisar Kebele, and Konso Special Woreda). A novel digestion method for leaf and seed samples was developed using an optimized acid mixture (2.5 : 0.75 : 0.5 of HNO 3 , HClO 4 , and H 2 O 2 ) at 240°C for 2 hrs and 30 min, resulting in clear and colorless solutions. The method makes the digestion process more efficient by minimizing the reagent volume, reducing digestion temperature and time, and simplifying the overall procedure. The efficiency of the optimized procedure was validated by spiking experiments, and the percentage recovery ranged between 94 and 110%. Under optimized experimental conditions, higher concentrations of essential minerals (K, Na, Ca, and Mg) were observed in the plant leaf and seed samples from the three areas. In addition, significant amounts of trace elements (Fe, Mn, Zn, and Cu) were also found. Importantly, no traces of the toxic elements (Cd and Pb) were detected in any of the analyzed samples, suggesting that the leaves and seeds of M. stenopetala are valuable sources of both micro- and macromineral nutrients and are safe from toxic metals. From a dietary perspective, the seed contains almost comparable concentrations of minerals as the leaves. As a result, the seeds of M. stenopetala can serve as an alternative source of minerals and play a role in overcoming the current global food crisis, particularly in the dry season. Analysis of variance at a 95% confidence level revealed significant differences in the levels of all mineral nutrients between the three sample means except K, Ca, Co, and Cu. Generally, the developed method includes an innovative digestion procedure that minimizes reagent consumption, operates at lower temperatures, and requires shorter digestion times, thereby optimizing resource utilization and maintaining analytical accuracy. Notably, the absence of toxic elements in the MP-AES procedure highlights the safety and reliability of M. stenopetala leaves and seeds as valuable, contamination-free sources of essential nutrients., Competing Interests: The authors declare that they have no conflicts of interest or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Ashenafi Shemnsa et al.)