Fluorescence Method for the Determination of Sulfate in Cement Sample

There is very weak fluorescence for the system of 0.1 mol/L HCl-4.0 mol/L propanetriol(TX-100)-0.05 mol/L BaCl₂. When SO₄^2- is added, Ba²⁺ reacts with SO₄^2- to form (BaSO₄)_n particles. The particle has two strong fluorescence peaks at 470 nm and 410 nm. The fluorescence intensity at 470 nm is linear to SO₄^2- concentration in the range of 2.0～80 μg/mL. The novel fluorescence method has been described for the determination of SO₄^2- in cement samples, with simple and sensitive. Its RSD is in the range of 1.9%～3.9%, and the recovery is in the range of 97.0%～102%.