A method for extracting sulfate from sphagnum peat

Abstract The efficacy of five solutions for extracting sulfate from a peat‐based medium was investigated. Extracting solutions used were 10 mM LiCl, 10 mM KC1, 100 mg/L P, 500 mg/L P, 0.15% CaCl2, or distilled water. Equilibration time affected the amount of sulfate extracted with the use of 100 mg/L P or distilled water extractants. Differences in the amount of sulfate extracted were observed at 0.5‐, 4‐, and 12‐hour equilibration times. Extraction effectiveness increased with the increase of equilibration time, up to a maximum of 4 hours. The concentration of sulfate extracted with all extractants levelled off at the 2‐hour equilibration time. CaCl2 was the most effective solution for the extraction of water‐soluble sulfate. Water‐soluble sulfate plus absorbed sulfate was most efficiently extracted with 500 mg/L P. No relationship was observed between measured sulfate and the pH levels of the extracted solutions.