T/ZJATA 0026-2024 Active

Scope: This document describes the spectrophotometric method using pre-prepared phosphomolybdenum blue (vanadomolybdenum yellow) reagents for determining total phosphorus in water. This document is applicable to the determination of total phosphorus in surface water, groundwater, domestic sewage, and industrial wastewater. When using the low-range method, the detection limit of this method is 0.01mg/L, the lower limit of determination is 0.04mg/L, and the upper limit of determination for undiluted water samples is 2.0mg/L. When using the high-range method, the detection limit of this method is 0.07mg/L, the lower limit of determination is 0.28mg/L, and the upper limit of determination for undiluted water samples is 30.0mg/L. Main technical content: The standard includes the method principle, instrumentation and equipment, reagents or materials, samples, detection steps, quality control, etc. It establishes a low-range method (potassium persulfate digestion-phosphomolybdenum blue pre-prepared reagent spectrophotometry) and a high-range method (potassium persulfate digestion-vanadomolybdenum yellow pre-prepared reagent spectrophotometry). The total phosphorus pre-prepared reagent is added to the water sample, and under neutral conditions, various phosphates are digested by potassium persulfate at high temperature, and all the phosphorus contained is oxidized to orthophosphate. In an acidic medium, a complex is formed, and the total phosphorus value is determined by spectrophotometry. Total phosphorus refers to the total amount of various forms of phosphorus in water, including dissolved, particulate, organic, and inorganic phosphorus. This method has the following advantages: 1) Reducing the amount of water samples and reagents taken, and reducing the amount of wastewater discharged; 2) Using pre-prepared reagents to reduce the impact of harmful substances on human health during reagent preparation; 3) The instrument comes with built-in curves, and the water sample co