GB/T 16489-1996 is a standard for the determination of sulfides in water quality. It adopts the Methylene Blue Spectrophotometric method, spec-trophotometry. Sulfides in water affect water quality, emit odor and are harmful to aquatic organisms. The standard specifies in detail the operation process of collecting and pretreating water samples, adding reagents to react with sulfides to generate methylene blue, and then using spectrophotometer measurement Absorbance to determine the sulfide content. The preparation and use of reagents, as well as the calibrating and determination conditions of the instrument are clearly stated. The method is easy to operate, has high Sensitivity, and is suitable for a variety of water samples. It provides a reliable means for the detection of sulfide content in water quality monitoring.