Revista de Ciências Químicas

A new, direct, rapid, simple, sensitive and accurate method for the determination of 2-Mercaptoethanol (Quick facts) or Mercury(II); The method is based on the using mercury (II) chloride solution as titrant (or reverse) in potentiometric titration depending on the first and second derivative differential procedure was used for all titrations; The method is suitable for the assay of 2-ME in micro amounts at a wide range of mass (15626.6-7.8133 μg) in 80 mL; The equivalence point is marked by a sharp peak in all instances and molar ratio of (Hg2+: 2-ME) at inflection point (1:2). Accurate and precise results were obtained with an average error % of (0.1333-0.5667%) and a Relative Standard Deviation of (0.70499-0.1957%) respectively.

This paper dwells on the general applications of geochemical techniques in coastal and urban environments; it enumerated the application of geochemical techniques in geological media, such as: groundwater resources, natural and marine water resources, sediments, soils, particulates and rocks. The latter part dwells on the application of geochemical techniques in oil and gas; and Nigeria, a country in West Africa was used as case histories. This paper aims at revising the application of geochemistry on a global perspective; it further aims at comparing the approach of the geochemical techniques in Nigerian oil and gas industries with the current global trends and methodologies. It has further deduced the needs for effective integration of geochemical and geophysical techniques for a result-oriented scientific research in oil and gas.

In this study, Coconut Coir Pith was used to prepare a low cost bio adsorbent through chemical modification. The effect of adsorbent dosage, contact time, initial metal-ion concentration, pH and temperature on the adsorption of nickel onto chemically modified coconut coir pith was investigated. The maximum removal was observed at pH 6.0 and adsorbent dose 2.0 g/L for initial metal-ions concentration 50 mg/L. Study of temperature effect proved that the process is endothermic. Langmuir and Freundlich isotherm models were used for equilibrium adsorption data. Langmuir isotherm proved to be a better fit. Pseudo first order and pseudo second order kinetic models were applied to analyze the kinetic mechanism of adsorption. The values of Gibbs free energy ΔG°, Enthalpy ΔH° and Entropy ΔS° was calculated by the thermodynamic studies.

The discovery of superconductivity in MgB2 and B-doped diamond has stimulated the search for new superconducting materials in similar systems containing light elements. In the framework of BCS theory, high frequency phonons induced in a network of light elements can yield a higher superconducting transition temperature (Tc). It shows that light element superconductors provide one of the most promising paths to a room-temperature superconductor taking account of the relationship electronic state and bonding state.

Micro- and millilitre-scale sensors have become increasingly important in modern biotechnology. Miniaturization and parallelization are also commonly employed in bio-analytical applications, environmental science and bioprocess engineering. This reduction of dimensions to the micro- and milliliter-scale stems from the demand for new sensor systems that enable non-invasive monitoring of bioprocesses in microfluidic or on-chip devices. Highly sensitive optical (bio-) sensors, with operating principles based on photoluminescence intensity or lifetime detection, hold significant promise for meeting the space-limited conditions within miniaturized biotechnological systems. In this context, the properties and applications of OLED-based organic sensors in biotechnology are discussed. The possible use of OLEDs as excitation sources in (analytical) biotechnological applications is also examined.