Lam Lik. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 107-112). / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Chemistry of portland cement manufacture --- p.1 / Chapter 1.2. --- Classical methods of cement analysis --- p.7 / Chapter 1.3. --- Application of instrumental methods in cement analysis --- p.12 / Chapter 1.3.1. --- X - ray fluorescence spectrometry --- p.12 / Chapter 1.3.2. --- Atomic absorption spectrometry --- p.16 / Chapter 1.3.3. --- Other instrumental methods --- p.22 / Chapter 1.4. --- Treatment of data --- p.25 / Chapter 1.5. --- Dissolution techniques for AAS analysis --- p.28 / Chapter 1.5.1 --- Hydrofluoric acid decomposition --- p.28 / Chapter 1.5.2 --- Fusion --- p.30 / Chapter 1.6. --- Research objective --- p.34 / Chapter Chapter 2. --- Analysis of Cement and Raw Meal Samples --- p.35 / Chapter 2.1. --- Experimental --- p.36 / Chapter 2.1.1. --- Reagents --- p.35 / Chapter 2.1.2. --- Instrumental --- p.37 / Chapter 2.1.3. --- Procedure --- p.37 / Chapter 2.1.3.1. --- "Sample solutions for the determination of SiO2, A1203, Fe2O3, Ti02, Na20 and K20" --- p.37 / Chapter 2.1.3.2. --- Sample solutions for the determination of CaO and MgO --- p.38 / Chapter 2.1.3.3. --- "Standard solutions for the determination of SiO2, Al2O3， Fe203, TiO2, Na2O and K2O" --- p.33 / Chapter 2.1.3.4. --- Sample solutions for the determination of CaO and MgO --- p.41 / Chapter 2.1.3.5. --- X-ray briquettes --- p.42 / Chapter 2.2. --- Results and discussion --- p.43 / Chapter 2.2.1. --- The proposed fusion system --- p.43 / Chapter 2.2.2. --- Instrumental conditions --- p.47 / Chapter 2.2.3. --- Accuracy --- p.56 / Chapter 2.2.4. --- Interferences studies --- p.61 / Chapter 2.2.5. --- "Calibration graph, detection limits and precision" --- p.69 / Chapter 2.2.6 --- Real sample analysis --- p.80 / Chapter Chapter 3. --- Analysis of Siliceous Materials and Coal --- p.84 / Chapter 3.1. --- Experimental --- p.84 / Chapter 3.1.1. --- Reagents and instruments used --- p.84 / Chapter 3.1.2. --- Procedure --- p.85 / Chapter 3.1.2.1. --- "Sample solutions for the determination of SiO2, A1203, Fe2O3, Ti02, Na20 and K20" --- p.85 / Chapter 3.1.2.2. --- Sample solutions for the determination of CaO and MgO --- p.85 / Chapter 3.1.2.3. --- "Standard solutions for the determination of Si02, Al2O3, Fe2O3,TiO2, Na20 and K20 in siliceous material and coal" --- p.86 / Chapter 3.1.2.4. --- Standard solutions for the determination of CaO and MgO --- p.87 / Chapter 3.1.2.5. --- X - ray briquettes --- p.88 / Chapter 3.2. --- Results and discussion --- p.88 / Chapter 3.2.1. --- Fusion of siliceous materials --- p.88 / Chapter 3.2.2. --- Fusion of coal --- p.93 / Chapter 3.2.3. --- Accuracy and precision --- p.95 / Chapter 3.2.4. --- Real sample analysis --- p.99 / Chapter Chapter 4. --- Conclusion --- p.103 / Chapter 4.1. --- Comparison of XRF and AAS as analytical means in the cement industry --- p.103 / Chapter 4.2. --- The proposed fusion system --- p.105 / References --- p.107

Digitized by Kansas Correctional Industries

Doppler-free saturation spectroscopy in an optically thick atomic vapor is used in an optical-feedback configuration for two semiconductor diode laser systems. One laser system consists of an unmodifed, commercially available diode laser. The other laser system consists of a diode laser initially stabilized by optical feedback from a diffraction grating. In both cases a portion of a 780-nm diode laser beam passes through a heated rubidium cell and is retroreflected back to the laser. The optical feedback causes the laser frequency to be stabilized to a hyperfine transition within the Rb D��� line. The linewidth of the laser is also reduced as a result of the optical feedback. / Graduation date: 1995

Graphite filter atomizers (GFA) for electrothermal atomic absorption spectrometry (ETAAS) show substantial advantages over commonly employed electrothermal vaporizers and atomizers, tube and platform furnaces, for direct determination of high and medium volatility elements in matrices associated with strong spectral and chemical interferences. Two factors provide lower limits of detection and shorter determination cycles with the GFA: the vaporization area in the GFA is separated from the absorption volume by a porous graphite partition; the sample is distributed over a large surface of a collector in the vaporization area. These factors convert the GFA into an efficient chemical reactor. The research concerning the GFA concept, technique and analytical methodology, carried out mainly in the author's laboratory in Russia and South Africa, is reviewed. Examples of analytical applications of the GFA in AAS for analysis of organic liquids and slurries, bio-samples and food products are given. Future prospects for the GFA are discussed in connection with analyses by fast multi-element AAS.

No description available.

No description available.

Thesis (Master)--İzmir Institute of Technology, İzmir, 2005. / Keywords: Mercury, atomic absorption spectrometry, gold, amalgamation, cold vapor. Includes bibliographical references (leaves 48-51).

Thesis (Master)--İzmir Institute of Technology, İzmir, 2005 / Includes bibliographical references (leaves 35-37).

Thesis (M.S.)--Brigham Young University. Dept. of Electrical and Computer Engineering, 2007. / Includes bibliographical references (p. 55-58).

This thesis includes a description of modifications of the Hilger atomic absorption apparatus, which was used for most of the work. These modifications were restricted to the atomiser and burner, which were replaced by a modified "Eel" flame. photometer atomiser-burner and resulted in improved sensitivity and instrumental stability for the atomic absorption of magnesium. A comparison of the performance of this unit with that of the unmodified Hilger apparatus is given. A "Handigas" butane-propane mixture)-air flame was used for most of this work, but a coal-gas-air flame was also studied and found to give slightly greater sensitivity. The method was found to be subject to interference from many elements. Strontium salts, employed as releasing agents to overcome the effect of other elements, were not completely effective as milligram amounts of several elements interfered even when strontium was present. Among the more serious interfering elements are: aluminium, iron, manganese and zirconium (less than 20 p.p.m. interfere); the alkali and alkaline earth metal salts (more than 200-500 p.p.m. interfere); phosphate (more than 100 p.p.m. P₂0₅ uranium (more than 4,000 p.p.m.); arsenate and vanadate. An attempt is made to explain the mechanism of some of these interfering effects. A combination of strontium salt and acetyl acetone was found to over-come the effects of small amounts of several elements that form complexes with acetyl acetone (e.g. iron and aluminium) far more effectively than strontium alone. Larger amounts of many interfering elements are removed by a solvent extraction procedure employing acetyl acetone and chloroform. Elements which cannot be removed by this means may be separated by anion-exchange, volatilisation, electrolysis or precipitation. A spiking technique, which compensates JT/GB for the effects of small amounts of interfering elements, is described and enables many samples to be analysed without prior separations. The method described has good sensitivity (the limit of determination is approximately 1 microgram of magnesium in 50 ml. of solution). It has been applied to the analysis of clay samples, iron ore, limestone and uranium metal, oxides and processing solutions. The coefficient of variation of the method was determined using two clay samples and results of 2.0 and 4.6 percent, at magnesium oxide concentrations of 0.65 and 0.22 percent respectively, wore obtained. The speed of the method compares favourably with others described for the determination of microgram amounts of magnesium, but increases if large amounts of interfering elements are present.