DETERMINATION OF LEAD IN SEAWATER BY ELECTROTHERMAL ATOMIC-ABSORPTIONSPECTROMETRY WITH TRANSVERSELY HEATED FURNACE BY USING OXALIC-ACID ORPD MG AS MODIFIERS/
Jy. Cabon et A. Lebihan, DETERMINATION OF LEAD IN SEAWATER BY ELECTROTHERMAL ATOMIC-ABSORPTIONSPECTROMETRY WITH TRANSVERSELY HEATED FURNACE BY USING OXALIC-ACID ORPD MG AS MODIFIERS/, Spectrochimica acta, Part B: Atomic spectroscopy, 51(9-10), 1996, pp. 1245-1251
The simultaneous volatilization of seawater salts and lead free atoms
induces chemical interferences. Moreover, an under-compensation relate
d to the vaporization of seawater salts is observed; the systematic er
ror depends on the magnitude of the background absorption signal to be
corrected and can be very important at low Pb concentrations. In the
presence of oxalic acid, which modifies the seawater matrix and promot
es a lower atomization temperature, the chemical interference is suppr
essed and the background absorption signal is dramatically reduced. In
the presence of the Pd/Mg modifier and nitric acid, Ph is stabilized
at a higher temperature and the major part of the seawater matrix can
be removed before atomization, but the integrated absorbance remains d
epressed. The detection limits obtained for 10 mu l of seawater in the
presence of oxalic acid or Pd/Mg and nitric acid used as modifiers ar
e respectively 0.3 mu g l(-1) and 0.5 mu g l(-1).