Recording total phosphorus and sodium tripolyphosphate assay separately

Trial design and interpretation

Use separate acceptance fields for phosphorus expressed as P₂O₅ and for STPP assay. The former does not establish that all phosphorus comes from the target salt. If rapid dissolution is required, also specify particle size and hydration time.

Recording Sodium tripolyphosphate assay

Sodium tripolyphosphate assay: use the agreed method. The old catalogue table contains a column mismatch. Use a specification signed off by the supplier. Total phosphorus (as P₂O₅): use the agreed method. Total phosphorus alone does not establish the STPP assay.

Should acceptance use P₂O₅ or STPP percentage?

List converted total phosphorus and sodium tripolyphosphate assay as separate measures. Request the method for each in the grade TDS. Detergent builder formulation: Compare dispersion, residue and dry-blend uniformity in the same formulation and water hardness.

What to record

• Total phosphorus
• Main salt assay
• Particle size
• Dissolution time at specified water temperature

Technical references

• ENVO public product information · Verify against the ordered grade and lot ↗

Products and processes