Study of the synergistic effect of 2-methoxy-4-formylphenol and sodium molybdenum oxide on the corrosion inhibition of 3CR12 ferritic steel in dilute sulphuric acid

The synergistic effect of the corrosion inhibition properties of 2-methoxy-4-formylphenol and sodium molybdenum oxide on the electrochemical property of 3CR12 ferritic stainless steel in 2M H2SO4 acid solution was assessed through coupon analysis, potentiodynamic polarization technique, IR spectroscopy and micro-analytical technique. Experimental data showed the combined admixture effectively inhibited the steel corrosion at the concentrations analyzed with a maximum inhibition efficiency of 94.47% and 89.71% from coupon analysis and potentiodynamic polarization due to the electrochemical action and inhibition of the steel by the ionized molecules of the inhibiting compound which influenced the mechanism of the redox reactions responsible to corrosion and surface deterioration. Results from corrosion thermodynamic calculations showed chemisorption adsorption mechanism. Infrared spectroscopic images exposed the functional groups of the molecules involved for the corrosion inhibition reaction. Micro-analytical images showed sharp contrast in surface morphology between the inhibited and corroded test specimens under study. Cracks, intergranular and pitting corrosion in addition to severe surface deterioration was observed in the uninhibited samples. Inhibitor adsorption fits the Langmuir isotherm mode

Magnetic molecularly imprinted polymer prepared by microwave heating for confirmatory determination of chloramphenicol in chicken feed using high-performance liquid chromatography-tandem mass spectrometry.

A magnetic molecularly imprinted polymer (MMIP) for chloramphenicol was prepared using a surface-imprinted and microwave-heating-induced polymerization method. The surfaces of the magnetic particles were first double-bond functionalized with 3-(trimethoxysilyl)propyl methacrylate (gamma-MPS), followed by the copolymerization of 4-vinyl pyridine (4-VP) and trimethylolpropane trimethacrylate (TRIM) in the presence of chloramphenicol as a template and 1,1-azobis(cyclohexane-carbonitrile) (ABCN) as an initiator in a mixture of dimethyl sulfoxide and water with microwave heating at 80 degrees C. The magnetic polymer possesses supraparamagnetic properties and was used to concentrate and cleanup chicken feed extract, followed by chromatographic separation using a Lichrospher (R) 100 RP C8 column and detection with two multi-reaction monitoring transitions at m/z 321 -> 152 and m/z 321 -> 257. The mean recoveries obtained at two spiking levels were in the range of 94.6-100% The relative intra- and inter-day standard deviations were in the range of 1.4-2.6% and 5.1-5.7%, respectively. The detection limit of the method was 0.12 mu g kg(-1). This confirmatory method was successfully applied to determine chloramphenicol in chicken feed samples

Corrosion inhibition properties of the combined admixture of essential oil extracts on mild steel in the presence of SO42− anions

The combined admixture of essential oil extracts, salvia officinalis and simmondsia chinensis was studied at low concentrations to assess their corrosion inhibition performance on mild steel in 1 M H2SO4 solution. Electrochemical studies were performed with potentiodynamic polarization test and weight loss analysis while open circuit potential measurement was employed to assess the thermodynamic stability of the corrosion properties of the compound with respect to time. Results obtained showed optimal inhibition efficiency of 86.58% and 83.29% at 6% and 5% volumetric concentration from the electrochemical test. The corrosion potential of the inhibited steel displaced significantly in the positive direction compared to the significant negative displacement of corroded steel due to surface coverage from the inhibitor molecules on the inhibited steel. Thermodynamic calculations showed chemisorption adsorption mechanism according to Langmuir, Frumkin and Freundlich adsorption isotherm models. Optical images of inhibited mild steel surface significantly contrast the corroded non-inhibited steel which showed the presence of surface oxides, general deterioration and macro pits. Keywords: Corrosion, Mild steel, Inhibition, Adsorptio