Page 145 - Inorganic Mass Spectrometry - Fundamentals and Applications

Inductively Coupled Plasma Mass Spectrometry 135

soils have been considered [327]. Analysis of marine sediments by ICP-MS was
assessed by using external calibration, standard addition, and isotope dilution
[328,329] with comparison of experimental results for standard reference mate-
rials. The influence of sample preparation on spectral overlaps was demonstrated.
Spectral overlaps due to molecular oxides can also present problems [327].
Total mercury in soils can be measured by ICP-MS [330].
extracted by using a microwave assisted flow injection system. A complexing
agent and surfactant were added to eliminate the long memory effects typically
observed with mercury.
A mobile ICP-MS has been used for on-site measurements of polluted soils
[331]. A rapid digestion procedure was developed in order to reduce sample
analysis time for the rapid identification of heavy metal anomalies near a mine
dump where no vegetation was growing.
Slurries have been used to introduce soil samples into an ETV with ICP-
detection [332] as well as directly into an ICP-MS using a ~abington-type nebu-
lizer [333]. Although slurry sample introduction eliminates the problems associ-
ated with sample dissolution, care is required to ensure that the slurry particles are
small enough to be completely vaporized in the ICP. Agglomeration of particles in
the slurry before introduction to the nebulizer must be prevented in order to
maintain constant transport efficiency into the ICP.

ly Ash, and Dust
Combustion of coal produces ash that can be transported through the air. Slag-
ging and fouling problems can also be predicted from elemental analysis. There-
fore, elemental analysis of both the coal as well as the ash are important.
dures for dissolution and analysis of coal and combustion products of coal have
been reported [334-3361. Laser ablation sampling has been successfully used for
coal and combusted materials [337,338]. The direct introduction of slurries has
also been used [339]. Comparison of ICP-MS and PKE analysis of coal combus-
tion aerosols showed that analysis errors can occur in ICP-MS particle vaporiza-
if
tion is incomplete in the ICP [340].
Flow injection hydride generation has been used measure As, Hg, and Se
to
in coals with detection limits in the 2- to 5-ng/g range [341]. Comparison of ICP-
MS and neutron activation analysis results showed good agreement.
ICP-MS isotope ratio measurements of house dust samples were used to
assess potential sources of Pb [342]. Street dust and soil outside the house showed
similar Pb isotope ratios, but lead paint in the house had a different isotopic
pattern. Sources of lead outside the home were found to contribute as much to
lead in most of the house dusts as did lead from lead-based paints inside the
house.
Dissolution of dust and other atmospheric aerosol smples by microwave