Note
An automated turbidimetric method for analysis of sulfate in saline water samples
was evaluated. Dilution of samples to yield a salinity of 1 ‰ or less was required to eliminate
ionic strength effects. The initial concentration of a saline sample requiring 1:100 dilution cannot
be < 1000 mg liter⁻¹ SO₄ ⁻² (10 mM), for a precision of 2-5% and an accuracy of 2-5 %. The limit
of detection, expressed as initial concentration of sample to be diluted 1:100, was 150 mg liter⁻¹
SO₄ ⁻² (1 .6mM). The method requires only 100 µl of saline porewater or seawater. Fifty samples
can be analyzed in an 8-hr day with 2 replicates per sample and 3 standard curves.