An attempt has been made to develop specialised flow injection analysis (FIA) systems for sulphate determination, and the determination of metals in trace quantities. The use of pH gradients and kinetic of recta in FIA systems is described, as is the use of single and double solvent extraction steps. The optimisation of the systems to improve sensitivity was carried out. The systems developed have many advantages over the static methods currently in use in analytical laboratories. Automation improves the precision and speeds up the analysis. Many of the chemical processes that classical "wet chemistry" involves have been automated, for example sampling, reagent addition, phase separation and absorbance measurement. The absorbance measurement was carried out using a phototransducer with LED light source. The detector cell is solid state. The inert stability of these components gives rise to very high sensitivity in colorimetric analysis. A system for the in-line measurement of pH is described. This was used to monitor pH gradients and the pH of solutions passing through the detector flow cell; for solvent extraction, and the mode of operation investigated. A robust easily constructed phase separator is described in single and double extraction systems, for the determination of trace quantities of uranium. The sulphate determination by turbidimetric analysis involved the use of alkaline EDTA. The build up of precipitated barium sulphate is minimised and interference masking is shown possible. FIA systems for the determination of copper(II), bismuth(III) and thorium(IV) with pyrocatechol violet are described. The pH effect was studied. Chelated zinc(II), copper(II) and nickel(II) with 1-(2-pyridylazo)2-naphthal(PAH) were extracted using single extraction system. Use was made of pH and kinetic effects to enable separate extraction of two metals from the same sample. The use of masking agents to allow the specific chelation of uranium in the presence of interferences was investigated. An indirect method using extraction of the uranium with tributylphosphate, then subsequent colour formation in the organic phase is described. The need for masking agents is thus minimised. The determination of the uranium content of ore is thus possible. A double extraction system for metal reconcentration was designed. The use of advanced optimisation and automation techniques is discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:635996 |
| Date | January 1982 |
| Creators | Baban, S. O. |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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