Suspensions of biological tissues in alkaline medium for the determination of copper, manganese and cobalt by electrothermal atomic absorption spectrometry

Electrothermal atomic absorption spectrometry was applied to the determination of copper, manganese and cobalt in biological tissues of which small amounts are available only. The samples (10 mg of mice tissue) were suspended in 1 mL of water containing tetramethylammonium hydroxide, Triton X-100 and silicone antifoam. The sample was homogenized by heating to 60 degrees C for 5 min, submitted to dilution if necessary, and injected into the atomizer. Wall atomization was used for Cu and Mn, and platform atomization for Co. Calibration was carried out using aqueous standards for copper and manganese determination. The determination of cobalt suffered from a matrix effect and, in this case, calibration was enabled by using a suspension of a cobalt-free muscle sample. The detection limits are 25, 20 and 62 ngg(-1). The results obtained for five certified reference materials demonstrated the reliability of the procedures for the determination of the three analytes in normal and dystrophic mice tissue.