Microwave digestion with HNO3-H2O2-HF for the determination of total aluminum in seafood and meat by inductively coupled plasma atomic emission spectrometry

A sample preparation procedure employing microwave digestion procedure is described for the determination of total aluminum in seafood and meat samples by inductively coupled plasma atomic emission spectrometry (ICP-AES). Lyophilized samples were first digested in closed vessels with HNO3 and HF. An additional digestion then proceeded in open vessels with H2O2. H3BO3 was employed to eliminate excess HF. Matrix effects of Ca, K, Mg, and Na, acid effects of HNO3, and possible spectral interferences were investigated. The influences of amount of HF on analytical results were observed. The recoveries of spike (95.2-97.6%) and the analyses of NIST standard reference materials 1566a (oyster tissues) and 1577b (bovine liver) demonstrated the reliability of the method. Twelve representative seafood and meat samples were analyzed, and the analytical results were compared with those obtained with HNO3-HClO4 digestion on a hot plate and with HNO3-H2O2 microwave digestion. It was shown that the digestion without the addition of HF was incomplete for the determination of total Al.