An ICP7AES spectrometer Spectroflame MODULA (Spectr
o Analytical Instruments, Kleve, Germany),
equipped with two monohromators: (i) spectral range
160 – 460 nm with nitrogen purged optics and (ii)
spectral range 240 – 790 nm with air purged optics,
was used. Background correction was performed. We
used the internal standard method by adding scandiu
m to the samples and standard solutions. The calibr
ation
was performed using three standard solutions in 2 %
v/v HNO
3
. A commercial multielement standard
solution with concentration 100 Pg/l was used as a
stock solution. The calibration standard solutions
had the
following concentrations: 0,0; 5.0 and 10.0 ppm.
With the aim to define the magnitude of the differe
nce between ICP and colorimetric P in the soils and
plant
material investigated, we analysed the same solutio
ns, obtained by the digestion methods described abo
ve,
following the colorimetric procedure for P determin
ation, described by Gorbanov
et al
. (1990)