Standard Operating Procedure

Subject: Preparing Saturated 2M Potassium Phosphate Tribasic (K₃PO₄)

Date: 20 November 2006

SOP # IA4

Prepared By: Christy Ackley

Approved By: Tarea Sanders

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Suggested Vendors, Catalog number, current price:

Potassium Phosphate Tribasic

Daigger FX449285GCC 500g $16.04

2M POTASSIUM PHOSPHATE TRIBASIC K₃HOP₄

• Prepare 200mL K₃HPO₄; store at room temperature

Instructions:

1. Weigh out 84.9g K₃HPO₄

2. Add to 200ml distilled water

3. Mix well

4. Quality check:

ü Add 1ml K₃HPO₄ to 5ml saturated calcium chloride, a precipitate should form immediately

ü If no precipitation takes place, drop pH by 1