Vi. Slaveykova et M. Hoenig, ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRIC DETERMINATION OF LEAD AND TIN IN SLURRIES - OPTIMIZATION STUDY, Analyst, 122(4), 1997, pp. 337-343
A comparative study of the efficiencies of W, Mg, Mg + Pd, Ir + Mg and
Ir + W + PO43- as chemical modifiers for the thermal stabilization of
Pb and Sn in slurries was performed, The Ir + Mg modifier contributes
more than the others to minimizing matrix effects and preventing doub
le peak formation, The influences of slurry concentration, amount of m
odifier and pyrolysis step on the integrated absorbance signals for Pb
and Sn in sediment slurry were studied, The potential of fractional f
actorial design was explored to evaluate the effect on the absorbance
signals of different factors such as drying and pyrolysis times, pyrol
ysis and atomization temperatures, presence of modifier and incorporat
ion of a 'cool-down' step in the electrothermal program, The Pb and Sn
integrated absorbance signals are increased by lower and higher pyrol
ysis and atomization temperatures, respectively, The Ir + Mg modifier
also increases the absorbance signal for Sn, The use of an Ir + Mg mod
ifier and ultrasonic agitation in the direct introduction of slurries
into the graphite atomizer provides a consistent performance with good
sensitivity, precision and analytical recovery.