Cuantificación de metales pesados (Hg, As, Pb y Cr) en organismos acuáticos: cangrejo rojo (Ucides occidentalis)

Abstract

The objective of this research was to determine by atomic absorption spectrophotometry (AAS), the concentration of heavy metals (lead, chromium, arsenic and mercury) in the soft tissue of the red crab (Ucides occidentalis). Catches were conducted in five sampling stations along the banks of the estuary Huayla, Machala, Ecuador, in October 2014. The specimens were placed in polyethylene bags and refrigerated until the time of analysis; 2.5 g of tissue samples from the cephalothorax was obtained and digested by wet oxidation to be analyzed by atomic absorption spectrophotometry. The results showed that the highest average concentration of lead (Pb) in soft tissue red crab was 13.5 ± 0.45 mg.kg-1 in the sampling station 3 and chromium (Cr) 8.84 ± 0, 06 mg.kg-1 in the sampling station 1. The highest concentration of arsenic (As) was 33.59 ± 0.38 mg.kg-1 in the sampling station 4 and mercury (Hg) 142.54 ± 0.39 mg.kg-1 in the sampling station 4. Therefore we conclude that in all sampling stations the content of heavy metals exceeds the ceilings set by the European Union (2014) for this type of food.

Keywords

• atomic absorption spectrophotometry
• cephalothoraxes
• Huaylá
• Ucides occidentalis
• wet oxidation