VAPORIZATION AND ATOMIZATION OF BORON IN THE GRAPHITE-FURNACE INVESTIGATED BY ELECTROTHERMAL VAPORIZATION INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

The vaporization and atomization of boron in the graphite furnace were investigated using both electrothermal vaporization inductively coupl ed plasma mass spectrometry (ETV-ICP-MS) and graphite furnace atomic a bsorption spectrometry (GFAAS). The results show that the majority of the boron is vaporized in molecular form and removed from the furnace at temperatures well below the appearance temperature of atomic boron. The effect of nickel nitrate chemical modifier on the vaporization of boron was also studied. The modifier is largely ineffective in preven ting loss of boron from the graphic furnace prior to atomization. The extent of this preatomization loss, both in the presence and absence o f the modifier, is reported. For the determination of boron by ETV-ICP -MS, the optimum sensitivity is obtained at a vaporization temperature of about 1800-degrees-C, i.e. well below the maximum possible vaporiz ation temperature. This sensitivity is enhanced by the addition of the nickel modifier.