MAGISTER SCIENTIAE

Arsenic has always played a major role in the environment and human life in general. From its earliest uses, in ancient times, as a poison to its most recent use, in medicine, as an anti-leukemia agent, this metal has fascinated mankind. This fascination has already yielded several surveys on its toxicity, concentration, source and specie. However, some approaches have not been fully explored. One of these is its occurrence in Phosphate bearing rocks and subsequent possible contamination offertilizers derived from these rocks. To this end, a new variation ofa speciation mechanism used, solvent extraction followed by ion-exchange, has been developed. Although this method has mainly been used in connection with marine samples, in this dissertation, it has been applied to solid samples. The levels of arsenic were then determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Phosphate bearing rocks, commercial fertilizers and soils were digested in HCI and speciated out as As (III), As(V), Mono Methyl Arsenic acid (MMAA) and Dimethyl Arsenic acid (DMAA). The effect of different organic phases were examined as well as two ion-exchange resins. Phosphoric acid, being an intermediate stage in the manufacture of diverse fertilizers, was also investigated. Due to the close relationship between arsenic and phosphorus, some steps in the method had to be reversed in order to yield better results. The resulting samples were analysed at two wavelengths, ie 188.979nm en 193.696nm. Although the values obtained at the two wavelengths differ by between O.Smg/kg and 1.Smg/kg, a simple t-test proves that the values are reconcilable. A micro concentric nebuliser was studied regarding its aerosol particle size, with a)l-LASER-particle analyser, and the detection limit ofarsenic. The second part of this study could not be completed due to the loss of the ICP. The following four nebulisers were compared: Micro-Concentri