Phosphate (P) was extracted from soil samples using
common soil extraction techniques: deionized water
(DI)
and ammonium oxalate (AmOx). Colorimetry (Murphy R
iley), electrospray ionization mass spectrometry
(ESI-MS)
,
and inductively coupled plasma (ICP) were used in
the P analysis. Mass spectrometry measured
considerably more phosphate than colorimetric analy
sis following DI extraction and showed a good
correlation with ICP for P analysis following AmOx
extraction. These results suggest that ESI-MS anal
ysis
may detect more than just inorganic P in soil extra
cts, as ionization and ion transport in ESI-MS may
convert
organic P into detectable phosphate ionsคำศัพท์เฉพาะทางเคมี