"This publication describes the procedures used in the Water Quality Division laboratories to determine the phosphorus concentration of detergents. A manual method published by the American Society for Testing and Materials (ASTM), modified to overcome the interference from borates, is used to analyze samples that have a phosphorus concentration close to the 20% P205 maximum specified in the Phosphorus Concentration Control Regulations. An automated method has been developed, using "Technicon AutoAnalyzer" equipment, that enables detergent samples to be screened for phosphorus content at a rate of 20 samples per hour"--Summary.