The determination of toxic heavy metals in freshwater prawn and marine prawn by neutron activation analysis / Noor Hasliza Mohd Hassan

The amounts of toxic heavy metals in freshwater and marine prawn were determined by using gamma spectroscopy. Once the concentrations are obtained the results were used to compare the concentration of toxic heavy metals in freshwater prawn and marine prawn and also to study the effect of location to toxic heavy metals concentration in prawn. The metals being considered in this analysis are lead, mercury, arsenic, cadmium and antimony. Long irradiation was used to determine the concentration of the toxic heavy metals in the samples of prawn. The samples were collected from various locations for freshwater and marine prawn. The gamma spectroscopy was used in this project to determine the amount of toxic heavy metals in prawn body. The method was used is very simple and after preparation of sample was completed, the sample was analyzed using gamma spectrometer. Mercury content in freshwater prawn was in the range 0.02-0.06 mg/kg, whilst mercury content in marine prawn was in the range 0.05-0.31 mg/kg. Lead content in fresh water prawn was in the range 0.83-1.68 mg/kg whilst lead content in marine prawn were in the range 0.45-2.82 mg/kg. Most of the samples did not contain cadmium except Scampi collected at Sungai Besar. Cadmium in this sample is 0.86mg/kg. Arsenic content in freshwater prawn was in the range 3.16-7.72 mg/kg, whilst the arsenic content in marine prawn was in the range 2.50-11.41 mg/kg. Antimony content in freshwater prawn in the range of 0.58-0.76 mg/kg, whilst antimony content in marine prawn is 0.41 mg/kg. Generally, the amounts of heavy metals in freshwater prawn were lowered compared to marine prawn.