Indirect spectrophotometric method for the determination of sulfide with background correction of sulfate in cement samples.

A new approach for the separation of sulfide from cement samples by chemically converting it to hydrogen sulfide and spectrophotometric determination was described. The method is based on converting the sulfide into hydrogen sulfide (H₂S) gas using hydrochloric acid (HCl) and Tin (II) chloride dihydrate (SnCl₂.2H₂O) to reducing the ferric ions present in the cement samples that will prevent interfering with a recommended method, the liberated H₂S gas was determined spectrophotometrically. This method provides a calculating the sulfide percentage in cement samples and using this percentage to background correction the percentage of the sulfate, which was calculated in an instrumental method, when using instrumental methods total sulfur will be determined, such as these instrumental methods, sulfide sulfur will be determined with the sulfate. The method was simple, rapid, sensitive, selective, accurate and the final orange-red solution was shown a maximum absorption at 510 nm. Beers law was obeyed percentage range of 0.04-0.4 S^2-% with a molar absorptivity (1.12 × 10⁴) L.mol⁻¹.cm⁻¹, and Sandell's sensitivity (5.34 × 10⁻²) µg.cm⁻². The limit of detection (LOD) and limit of quantification (LOQ) were calculated as sulfide percentage and its values are 0.0081 S^2-% and 0.0024 S^2- %, respectively. [ABSTRACT FROM AUTHOR]