Abstract: A high wavelength fluorescent probe, Nile Red, was added to four proteins, viz., bovine albumin, alpha 1-acid glycoprotein, beta-lactoglobulin and ovomucoid. Nile Red showed an enhancement in fluorescence and a shift in emission wavelength, suggesting it was bonding hydrophobically to these proteins. Drug displacement of Nile Red from alpha 1-acid glycoprotein was achieved with both D,L-propranolol and flufenamic acid, showing that the binding site is less electrostatic and more hydrophobic in nature. In order to monitor these interactions, a simple spectrofluorimeter was constructed from solid-state components; the sensitivity of this instrument compared well with that of standard laboratory spectrofluorimeters.

Abstract: Within analytical chemistry, chromatography is by far the most widely used analytical technique. Gas chromatography (GC) and (high-performance) liquid chromatography (HPLC) have gained widespread acceptance in numerous application areas. As both gases and liquids can be used as the mobile phase in chromatography, extending the range of mobile phases to the supercritical region is but a logical step. Since supercritical fluids combine many characteristics of gases and liquids it is not surprising that SFC can be seen as an intermediate technique between GC and HPLC. Potential advantages of (carbondioxide based) SFC in comparision with LC include the compatibility with various GC detectors and the increased speed of analysis. In comparison with GC, SFC is advantageous for the analysis of high relative molecular mass or thermally labile components.

Abstract: An historical account of the concepts of chaos, its unpredictability and the complexities of non-linear systems are discussed.