Test method for determination of phosphorus content laundry detergent formulation2

1970 - 01 - 01 phosphorus content determination of laundry detergent formulation test method: sample digestion: accurate say 1. 500 g commercial detergent samples, 10 ml perchloric acid digestion, then heating in 10 ml of hydrogen peroxide to top up, be repeated until the samples thoroughly with a white solid, deionized water dissolved, the capacity to 250 ml. Phosphorus molybdenum blue color test solution: precise quantitative standards or move will take to test solution in 25 ml colorimetric tube, to participate in a moderate amount of ammonium molybdate - Dilute sulfuric acid solution, a moderate amount of reducing agent, to near scale, shake well, boiling water bath heating will time out after cooling, deionized water diluted to scale. Phosphorus standard solution and sample determination: laundry detergent sample solution are conducted in the optimization of experimental conditions of phosphorus molybdenum blue color, with ammonium molybdate - Sulfuric acid solution as the blank reference, choose 1 cm color dish in the determination of maximum absorption wavelength of 630 nm absorbance. A: on the shortcomings of inferior detergent equipment?