Environmental assessment of heavy metals and organotin compounds in Cape Town harbour, monitoring geochemistry and toxicity

Abstract

Analytical methods for speciation of targeted organotin compounds (TBT and TPT) in water samples using SPE cartridge and liquid-liquid extraction has been carried out. Also, sediment analysis using methanol - acid digestion and acid- sonication extraction methods were also developed. Different parameters affecting extraction and peak resolution were optimised. Also, three derivatisation procedures were optimised. The accuracy of the extraction procedure was also verified on certified reference material (BCR - 462) certified for TBT (54 ± 15 µg/kg) and DBT (68 ± 12 µg/kg). Freeze - dried mussel tissue (ERM - CE 477) certified for TBT (2.20 ± 0.19 mg/kg), DBT (1.54 ± 0.12 mg/kg) and MBT (1.50 ± 0.28 mg/kg). Good recoveries were obtained with methanol - acid digestion. The results were validated by analysing the real water and sediment samples collected from Cape Town harbour and the compounds were detected in both water and sediment samples, respectively.