We present two new methods for purifying dinosterol (4a,23,24-trimethyl-5a-cholest-22E-en-3b-ol) from sediments for the purpose of hydrogen isotope analysis via gas chromatography–isotope ratio mass spectrometry (GC–IRMS). The first method uses reversed phase-high performance liquid chromatography (RP-HPLC) to purify dinosterol from structurally similar 4a-methyl sterols that co-elute on GC ana...

502 What is MELC? Microemulsions are stable, isotropically clear solutions consisting of an oil (such as octane) and water stabilized by a surfactant and co-surfactant. To form such a mixture the interfacial tension between the oil and water has to be decreased by the addition of both a surfactant and a cosurfactant. Sodium dodecyl sulphate (SDS) is a common and widely used surfactant.1,2 Mediu...

The covalent grafting of carboxyphenyl functionalities to planar carbon substrates by reaction with 2-carboxybenezenediazonium salt has been studied in aqueous acid solution. The surface was characterized, before and after the functionnalization process, by cyclic voltammetry, electrochemical impedance spectroscopy and linear sweep voltammetry (LSV) in order to control and to prove the formatio...

In the present research, 4, 4'-biphenol was used as a homogeneous mediator for determining cysteine (CySH) on a Glassy Carbon Electrode (GCE). To describe the electrochemical properties of 4,4'-biphenol and to examine its electrocatalytic impacts on cysteine oxidation, both Cyclic Voltammetry (CV) and Linear Sweep Voltammetry (LSV) were employed. Our findings revealed that 4,4'-biphenol could s...

Due to the proteomics revolution, multi-dimensional separation and detection instruments are required to evaluate many peptides and proteins in single samples. In this study, electrospray ionization (ESI) ion mobility spectrometry (IMS) was evaluated as an additional separation after HPLC separations. Common HPLC mobile phase compositions (solvents, acid modifiers, and buffers) were assessed fo...

BACKGROUND Central Middlesex Hospital, in northwest London, has screened neonates for hemoglobinopathies, using the established manual technique of isoelectric focusing (IEF) since 1989. Recently, this laboratory has faced a large increase in the number of samples tested per year. This study compared the detection of hemoglobin abnormalities between the existing manual IEF method and that of au...