An electrochemical sensor based on an amino-functionalized iron NH2-MIL-101(Fe) metal-organic framework (MOF)/Pd nanoparticles (NPs) composite-modified screen-printed electrode (SPE) is prepared for the simultaneous determination of norepinephrine (NEPI) and acetaminophen (ACP). The NH2-MIL-101(Fe) MOF/Pd NPs/SPE electrochemical sensor shows a significant enhancement in the response peak current of NEPI, as compared to bare SPE. This suggests that the unique features of NH2-MIL-101(Fe) MOF/Pd NPs composite-modified SPE improve the electrocatalytic oxidation of NEPI. Such a synergistic effect between NH2-MIL-101(Fe) MOF and Pd NPs results in a significant enhancement in the response, where the MOF's high surface area combines with the high electron-transfer rate and the abundance of catalytically active sites afforded by the Pd NPs. The differential pulse voltammetry (DPV) method was obtained for quantitative determination of NEPI and high sensitivity was observed in NEPI determination with the calibration slope of 0.0327, µA µM-1. The developed NH2-MIL-101(Fe) MOF/Pd NPs/SPE sensor presents a low limit of detection of 0.007 µM toward NEPI determination. The developed NH2-MIL-101(Fe) MOF/Pd NPs/SPE sensor shows a good catalytic activity for the oxidation of NEPI and ACP, with anodic peak potentials of 360 and 550 mV, respectively. The separation of anodic peak potential is sufficient to enable simultaneous determination. Finally, the suggested sensing platform has confirmed suitable for the simultaneous determination of NEPI and ACP in real samples (pharmaceutical formulations and urine samples), achieving recovery values ranging from 97.1 to 104.4 % with relative standard deviations ≤3.6 %.
A new optoelectronic flow injection method is proposed for the determination of ferrous ions (Fe 2+ ) based on thiocyanate complexation to form a deep-red FeSCN 2+ complex.
The aim of this work was to develop and validate a rapid and low cost method for estimation of ibuprofen in pharmaceutical suspensions using Reverse-Phase High Performance Liquid Chromatography. The proposed method was conducted and validated according to International Conference on Harmonization (ICH) requirements. The chromatographic parameters were as follows: column of octyldecylsilyl C18 with dimensions (150 × 4.6) mm, mobile phase composed of acetonitrile with phosphoric acid with a ratio of 50 to 50 each using isocratic mode, flow rate of 1.5 mL/min and injection volume of 5 μL. The detection was carried out using UV detector at 220 nm. The method was validated and showed short retention time for ibuprofen peak at 7.651 min, wit
... Show MoreA simple, precise, and sensitive spectrophotometric method has been established for the analysis of doxycycline. The method includes direct charge transfer complexation of doxycycline withp-Bromanil in acetonitrileto form a colored complex. The intensely colored product formed was quantified based on the absorption band at 377 nm under optimum condition. Beer’s law is obeyed in the concentration range of 1–50 μg.mL-1 with molar absorptivity of 1.5725x104 L.mol-1.cm-1, Sandell's sensitivity index (0.0283) μg.cm-2, detection limit of 0.1064 μg.mL-1, quantification limit 0.3224 μg.mL-1 and association constant of the formed complex (0.75x103). The developed method could find application in routine quality control of doxycycline and has
... Show MoreStable isotope composition of δ2H and δ18O was investigated in the water resources of the Shwan sub-Basin northeast of Iraq. The study objects conceived the possible factors that affect the stable isotopes’ composition in precipitation additionally to achieve information concerning recharge processes and estimate the groundwater recharge sources. In this study, four precipitation samples were collected at the study area for the 2020–2021 hydrological year. Thirty-two groundwater samples and one surface water sample from Lesser Zab River (LZR) were collected during the same period for two sampling seasons. The results of observed meteorological data show a very small amount of pr
The synthesis and characterization of Schiff base and the complexities of metal ions and the evaluation of its antioxidant activities against 1.1-Diphenyl-2-picrylhydrazyl (DPPH) will compared with standard natural antioxidants and ascorbic acid. These prepared materials gave results are due exhibit excellent radical scavenging activities for all complexes with new prepared from reaction Schiff base and metal ions for [ Mn(II), Zn (II), Cd(II), Pd(II) and Hg(II) ]. The complexes prepared characterization by spectral methods (ultraviolet visible, infrared and mass spectra) will be identified in addition to the element micro analysis, (F.A.A.), magnetic sensitivity. The molar conductance values indicated that the complexes derived from Mn(II)
... Show MoreTo assess the contribution of Doppler broadening and examine the
Compton profile, the Compton energy absorption cross sections are
measured and calculated using formulas based on a relativistic
impulse approximation. The Compton energy-absorption cross
sections are evaluated for different elements (Fe, Zn, Ag, Au and Hg)
and for a photon energy range (1 - 100 keV). With using these crosssections,
the Compton component of the mass–energy absorption
coefficient was derived, where the electron momentum prior to the
scattering event caused a Doppler broadening of the Compton line.
Also, the momentum resolution function was evaluated in terms of
incident and scattered photon energy and scattering angle. The res