Standards.
Phosphate standards (standard P solutions) rangin
g from 3.4 ppm P to 31.6 ppm P were prepared
by serial dilution in DI water starting from a conc
entrated phosphoric acid solution. All phosphate s
olutions were
then standardized by Murphy Riley.
16
A 350 ppm chlorate standard was prepared by dissolv
ing 0.2567 g potassium chlorate in 500 mL DI water.
This solution was used as an internal standard to c
orrect for variability in the Varian MS instrument
and to
normalize ion peaks in the MS spectrum