Formaldehyde content of selected fish from the wet markets of Kathmandu valley

In Nepal, the supply of fish inside the country does not meet the domestic need and is imported from neighboring countries mainly from India. Therefore, fishes are stored in ice for a long time before they arrive to the local market in Nepal. Thus, there is a high chance of treating the fish with formaldehyde solution (formalin) to preserve the shelf life. An attempt was taken to assess the fish quality by investigating the concentration of formaldehyde and pH in selected fish available in Kathmandu city. From three different local markets, six species of fishes were collected and quantitative determination of formaldehyde was performed using UV-Vis spectrophotometer. The study indicates the mean range of formaldehyde from 0.393±0.004 μg g-1 to 2.328±0.304 μg g-1. Of the species analyzed Magur contained the highest concentration of formaldehyde (2.328±0.304 μg g-1). The pH was found to be in the range of 6.