Microwave digestion methods for the determination of trace elements in brain and liver samples by inductively coupled plasma mass spectrometry.

摘要: Two microwave digestion systems (open-focused and closed-pressurized) were tested for the mineralization of human brain bovine liver (NIST SRM 1577a) as dissolution steps prior to determination 16 trace elements (Bi, Cd, Co, Cs, Cu, Fe, Hg, Mn, Mo, Pb, Rb, Sb, Sn, Sr, Tl, Zn) by inductively coupled plasma mass spectrometry (ICP-MS). Digestion parameters (mass sample, mixture, power/time steps) optimized using temperature pressure sensors. Digestions with open-focused system require larger volumes conc. HNO3 30% H2O2 than digestions closed-pressurized system. Both produce correct results samples. The concentrations obtained digests tend be less precise from “closed-pressurized” digests. Because “open-focused” must diluted 50 mL bring acid concentration 0.7–2.0 mol/L required ICP-MS (closed-pressurized need only 20 mL), detection limits are higher digestor. digestor cannot handle more 150 mg tissue, whereas can mineralize 470 mg. latter method gave better tissue preparation reference material in samples is described.