Alternatively, for direct energy coupled devices: After the Sec. 7.2 “NOTE”
step has been completed and the sample has cooled for 5 minutes, add slowly 10 mL
of 30% H O . Care must be taken to ensure that losses do not occur due to 2 2
excessive vigorous effervesence. Go to Section 7.2.3.
7.2.2 Continue to add 30% H O in 1-mL aliquots with warming until the 2 2
effervescence is minimal or until the general sample appearance is unchanged.