The extraction technique providing the highest recovery of ATP (99.5%)
was as follows: 4 g of soil shaken with 25 mL 0.3M NaOH + 0.05M
Na2EDTA for 1.5 hours, filtered through Whatman 42 filter paper (or
centrifuged for 15 min at 10,000 rpm), adjusted to a pH of 6 and filtered
(0.45 11m) prior to HPLC analysis. Since this combination produced the
highest percentage of recovery, it was used for all of the subsequent
nucleotide extractions.
Extraction of IHP with the NaOH-EDTA extractant proved to be
problematic. Alternative extraction solutions were investigated to
determine compatibility with IHP and the analytical technique.
Standards containing IHP were subsequently prepared using extracting
solutions consisting of 0.5 M HC1, [61 5% tri-chloroacetic acid,[221 and 5%
acetic acid.