TEST SUMMARY
Organic material in the sample is destroyed and phosphorus in the sample is converted to phosphate ion by oxidation with sulfuric acid+ nitric acid+ hydrogen peroxide. When the phosphorus content is <2 %, the molybdovanado photometric method is used; when the phosphorus content is >2 %, the magnesium pyrophosphate gravimetric method is used.
TEST PRECISION
See figures below.
The bias of this test method has not been determined.