The ability to measure the absorbance of diatomic molecules (PO
and NO), together with the use of low sensitivity alternative lines to
adjust sensitivity, enabled simple and fast sequential determination of
N, P, and K in fertilizers using HR-CS FMAS and HR-CS FAAS after introduction
of a single aliquot of sample. The use of hydrogen peroxide permitted
analysis of fertilizers containing nitrogen in the forms of nitrate,
ammonium, and urea. The proposed technique combines the strengths
of simplicity and effectiveness of atomic absorption spectroscopy with
the ability to use the same sample preparation and dilution for all
three analytes. Overall, the proposed procedure offers major advantages
over traditional methods in terms of laboratory throughput, cost, and
time, because only a single sample preparation and analysis procedure
is required to evaluate NPK fertilizers.