Comparative study of different wet mineralisation digestion methods for the measurement of total mercury in biological samples

Three botanical substrates and one milkpowder were mineralised and digested by the following methods in order to measure their total mercury content: (1) HF/HNO3-KMnO4; (2) H2SO4/HNO3-KMnO4; (3) H2SO4/HNO3- H2O2; (4) H2SO4/HNO3-UV irradiation/KMnO4; (5) H2SO4/HNO3/V2O5-catalyst KMnO4 and (6) H2SO4/HNO3/V2O5-catalyst H2O2. Of these methods (1) and (5) yield similar results and produce relative standard deviation values between 0.8 and 7.6. Method (5) is the faster of the two. No interferences with the detection of Hg were observed