Determination of Aluminum in Fungus by Inductively Coupled Plasma Atomic Emission Spectrometry with Microwave Digestion

Excessive intake of aluminum may bring certain health risks, and the relevant standards and references lack the determination method of aluminum in fungus, so the title method was proposed, and the effect of hydrofluoric acid in the digestion system was discussed. 0.250 0 g of dried fungus sample was taken into digestion tube, 5 mL of nitric acid, 1 mL of 30% (mass fraction) hydrogen peroxide solution and 0.5 mL of hydrofluoric acid were added. The mixture was placed overnight after closing the lid, and digested according to the microwave digestion procedure on the next day. After removing the acid, washing, and making up the volume with 2% (volume fraction) nitric acid solution, the aluminum in the sample solution was determined by inductively coupled plasma atomic emission spectrometry at the detection wavelength of 396.152 nm. It was shown that the determined values without adding of hydrofluoric acid were significantly lower than the certified values, while the determined values after adding hydrofluoric acid were within the uncertainty range of the certified values. Linear relationship between values of the mass concentration of aluminum and its corresponding emission intensity was kept within 10.0 mg·L^-1, and the detection limit was 5.9 μg·L^-1. Tests for precision and spiked recovery were carried out on standard materials for biological component analysis, giving RSDs (n=6) of the determined values in the range of 4.0%-8.5%, and the recoveries were 89.0%-97.3%. The proposed method was applied to the analysis of 10 fungus samples, and the determined values were 203-305 mg·kg^-1.