The common methods for determining inorganic soil sulfate may be affec
ted by the extraction of sulfate from organic sulfur compounds such as
ester sulfates. In order to test this, various synthetic organic sulf
ur compounds (ranging from ester sulfates to sulfonates and C-bonded s
ulfur) were extracted with deionized water or with two common sulfate
extractors (0.5 M NaHCO3 and 0.02 M NaH2PO4). Similar amounts of disso
lved sulfate were detected in all extracts of the aromatic ester sulfa
te hydroxyquinoline sulfate. Sulfate was not released from aliphatic e
ster sulfates or C-bonded sulfur. Ion chromatography was compared to a
turbidimetric method for the determination of sulfate. The latter met
hod, based on BaSO4-precipitation, appeared to be unsuitable for deter
mining sulfate in organically influenced solutions .Barium precipitate
d sulfate as well as ester sulfates. Furthermore, the photometry of Ba
SO4 was influenced by specific absorption of dissolved organic compoun
ds, leading to a misinterpretation of the sulfate concentration in the
solution.