0.5M EDTA pH 8.0 Recipe

EDTA 0.5 M (pH8.0)

    0.5M, 1L:  148 g EDTA
                       + ~30-40 g NaOH to adjust pH
                       (or 186 g EDTA-Na.2H2O + ~20 g NaOH)
   Note: pH adjusted by NaOH is essential for solubility. Autoclavable

Reference