“…Iyengar and Sansoni (1980) discuss pretreatment of biological materials in an IAEA technical report. Some of the same references presented in the preceding section on sample collection and storage also have information on pretreatment : Stoeppler 1997a, b, Müller and Eckard 1997, Ostapczuk 1997a, Helmers 1997, Del Castilho and Breder 1997, Osberghaus and Helmers 1997, Schladot and Backhaus 1997, Wagner 1997, Rechenberg and Bachmann 1997a, Matter and Stoeppler 1997, Sansoni and Iyengar 1978, Iyengar 1986, Riley et al 1975, Grasshoff et al 1999, Brügmann and Kremling 1999, Kremling and Brüg-mann 1999, Rossbach et al 1992, Lewis et al 1992, Eschnauer and Stoeppler 1992, Salbu and Oughton 1995, Quevauviller 1995, Woittiez and Sloof 1994, Walton and Hoffman 1959, Schuller and Egan 1976, Marshall 1993). …”