R. Nowka et al., Analysis by solid sampling graphite furnace atomic absorption spectrometry: Success with some difficult samples, CHEM ANAL, 45(3), 2000, pp. 403-414
It is shown that direct solid sampling graphite furnace atomic absorption s
pectrometry (SS-GFAAS), equipped with a transversely heated graphite atomiz
er and an efficient deuterium background correction can be a powerful alter
native for the trace analysis of heavy metals in different materials. The d
irect solid sampling technique has been successfully applied to the analysi
s of cements (Cd, Pb and Cr), calcium fluoride single crystals (Cd and Pb),
barytes (Cd, Pb and Cu) and deposits of the surface of historical building
s (Pb, Cr and Mn) using the platform technique in a very wide concentration
range (upper-ppm to sub-ppb range). The analytical results from the SS-GFA
AS were compared with those obtained by Zeeman-GFAAS or FAAS after microwav
e aqua regia extraction and/or aqua regia-hydrofluoric acid digestion. In m
any cases good agreement was achieved with values obtained by reference met
hods. When using test sample masses between 0.029 to 0.756 mg an overall pr
ecision of about 10% RSD was obtained after standard calibration using diff
erent masses of certified reference materials (CRMs) such as sediments and
soils. Difficulties which can arise in special cases - like calibration pro
blems, relatively bad precision, poor agreement with reference methods - ar
e shown and discussed.