Optimization of an acid digestion procedure for the determination of Hg, As, Sb, Pb and Cd in fish muscle tissue

A simple, efficient and cost effective method was developed and optimized for the digestion of fish tissue for the determination of Lead, Cadmium, Mercury, Antimony, Arsenic and Selenium by FAAS, CVAAS and HGAAS. Three of the more common classical open tubed acid digestion procedures were explored with the purpose of optimizing the variables and selecting the single most efficient, convenient and inexpensive digestion method. The effect of parameters such as digestion media, digestion time and digestion temperature on the efficiency of extraction of heavy metals from fish tissue was examined. Concentrated nitric acid was determined to be the most efficient digestion media for all the metals studied. • Efficient extraction of Arsenic, Selenium, Antimony, Lead and Cadmium was achieved at a digestion temperature of 100 °C for 120 min. • Optimum extraction of Mercury in fish tissue was achieved at 85 °C for 120 min since at higher temperatures, mercury was lost due to volatilization.