Fish sauce (1 mL) samples were diluted in 3-M nitric acid (20 mL) and were incubated at 200 C for 8 h in a conical beaker
using a hot plate. Samples were then diluted to 100 mL with distilled water and were analysed using an inductively coupled plasma analysis emission spectrometer (ICP-AES; IRIS Advantage/SSEA, Jarrell-Ash Co. Ltd., Tokyo, Japan). Results are
presented as the mean ± standard error of three independent experiments.