GB/T 11220.1-1989

This standard specifies a spectrophotometric method for determining uranium content in soil samples, using CL-5209 extractant-containing resin for separation and 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol as a chromogenic reagent. It is applied in environmental monitoring and soil contamination assessment, particularly for detecting uranium levels in soils near mining sites, nuclear facilities, or areas affected by radioactive pollution. The method provides a quantitative basis for evaluating soil radioactivity and guiding remediation efforts.