using the extraction method discussed above. E51 The NaOH-EDTA extracting
solution had the same retention time as AMP, so it was difficult to
quantitatively measure the concentration of AMP in these samples.
The HPLC method for IHP separation was more problematic, because the
mobile phase was sensitive to changes in pH, which caused difficulties with
peak separation. Mobile phase preparation required careful pH adjustment
and re-equilibrating the column to obtain consistent and reproducible
separation of IHP.
Extraction of Organic Phosphorus Compounds
There was a decline in ATP and ADP recovery from soil as soil
reactivity increased (due to an increase in clay, organic matter, and Fe + Al
content) following the trend Blanton = Cecil > Belhaven (Fig. 4). There
was no significant difference in ADP recovery on the Blanton and Cecil
soils, but there was a significant difference between these two soils and the
Belhaven soil. The trend in percent recovery of ADP followed the order
Blanton = Cecil > Belhaven.
When the NaOH-EDTA extraction method was tested for IHP, there
was an observable decrease in the peak area of the standards prepared in
the extraction matrix compared with those prepared in water. The peak
area of the IHP in the alkaline extracting solution was approximately
half of that resulting from the same IHP concentration dissolved in