Linear calibration graph applicable to the indirect determination of sulphate

Equations based on the equilibrium relationship between a sulphate-containing solution and solid lead sulphate were derived and applied to calibration graphs for the determination of sulphate. The special character of the linear graphs extends not only the applicability of linear calibration and standard addition procedures to the indirect determination of sulphate, but also the reliability of the analytical results. Experiments with the flow-injection technique confirmed the applicability of the proposed linear graphs.