Mercury Determination in Fish Using Cold Vapour-Atomic Absorption Spectrometry (CV-AAS) with Sodium Borohydride (NaBH4) as the Reductor

Abstract

Marine fish can potentially accumulate heavy metal pollutants, such as mercury, from anthropogenic activities that can harm people who consume it. Marine fishes like Bandeng fish (Chanos chanos), Banjar fish (Rastrelliger kanagurta), Bawal Hitam fish (Parastromateus niger), Selar Kuning fish (Atule mate), Tenggiri fish (Scomberomorini), and Tuna fish (Thunnini) are consumed a lot by people in Bandung City. All these fish were analyzed using the CV-AAS method with the United States – Environment Protection Agency (USEPA, 2006), and the reducing agent was replaced by stannous (II) chloride with sodium borohydride. Variations in the sample preparation process include drying the sample using an oven and freeze dryer. SEM-EDX in the frozen-dried samples shows that the fibbers’ morphology is intact, while the fibbers are damaged in the hot-dried samples. During characterization using FTIR, there is a slight shift in wave number. The mercury concentrations obtained from every sample were below 0.5 mg/kg based on the Indonesian National Standard (SNI) 2009 standard for total mercury in fish. Therefore, it can be concluded that the samples are safe to be consumed. Validation methods showed that 0.3% sodium borohydride as the reductor can be used to analyze mercury and replace stannous (II)chloride. However, further studies are needed to determine the optimal concentration of sodium borohydride (NaBH4) in the marine fish samples as a reduction agent.