Ho Chak Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 122-126). / Acknowledgment --- p.i / Table of contents --- p.ii / List of figures --- p.iv / List of tables --- p.v / Abstract --- p.ix / Chapter Part I --- Determination of sulphide / General introduction --- p.1 / Spectrophotometric determination of sulphide --- p.5 / Chapter 1. --- Introduction --- p.5 / Chapter A. --- Review of the reported methods for the determination of sulphide --- p.5 / Chapter B. --- General description of the proposed method --- p.13 / Chapter 2. --- Experimental section --- p.18 / Chapter A. --- Preservation of samples --- p.18 / Chapter B. --- Sample pre-treatment --- p.19 / Chapter C. --- Separation/preconcentration of sulphide --- p.19 / Chapter D. --- Spectrophotometric determination of sulphide by proposed method --- p.24 / Chapter E. --- Spectrophotometric determination of sulphide by standard methylene blue method as the counter-check method --- p.32 / Chapter 3. --- Results and discussions --- p.34 / Chapter A. --- Optimization of the proposed spectrophotometric method --- p.34 / Chapter B. --- Optimization of the separation/preconcentration methods --- p.45 / Chapter C. --- Construction of the calibration graph for the spectrophotometric determination of sulphide and determination of the molar absorptivity coefficient --- p.53 / Chapter D. --- Precision and detection limit of the proposed spectrophotometric method --- p.54 / Chapter E. --- Interferences studies of the proposed method --- p.56 / Chapter F. --- Spectrophotometric determination of sulphide in water --- p.60 / Chapter G. --- Spectrophotometric determination of sulphide in beers --- p.63 / Chapter H. --- Spectrophotometric determination of sulphide in orange juices --- p.66 / Chapter 4. --- Conclusions --- p.68 / References --- p.70 / Chapter Part II --- Determination of fluoride / General introduction --- p.75 / Spectrophotometric determination of fluoride --- p.78 / Chapter 1. --- Introduction --- p.78 / Chapter A. --- Review of the reported methods for the determination of fluoride --- p.78 / Chapter B. --- General description of the proposed scheme for the spectrophotometric determination of fluoride in animal feeds --- p.84 / Chapter 2. --- Experimental Section --- p.87 / Chapter A. --- Ashing of the animal feed samples --- p.87 / Chapter B. --- Reduction of interferences in the ashed sample solutions using anion exchange resin --- p.89 / Chapter C. --- Preparation of solutions for the calibration graph and the ashed sample solutions for the spectrophotometric measurement --- p.90 / Chapter D. --- Spectrophotometric determination of fluoride in the ashed samples --- p.92 / Chapter E. --- Potentiometric determination of fluoride in the ashed sample solutions by the FISE method as the counter-check method --- p.93 / Chapter 3. --- Results and discussions --- p.94 / Chapter A. --- Ashing conditions of the animal feed samples --- p.94 / Chapter B. --- Removal of the interferences in the ashed sample solutions --- p.99 / Chapter C. --- Construction of the calibration graph for the spectrophotometric determination of fluoride --- p.112 / Chapter D. --- Precision of the spectrophotometric method --- p.113 / Chapter E. --- Spectrophotometric determination of fluoride in animal feeds --- p.114 / Chapter F. --- Potentiometric determination of fluoride in animal feeds by the FISE method as the counter-check method --- p.117 / Chapter 4. --- Conclusions --- p.120 / References --- p.122