GENERAL TIPS 1 :::---  A small amount of the sample is acidified with Concentrated Nitric Acid to which a little ammonium molybdate is added. The presence of Phosphate Ions is indicated by the formation of a bright yellow layer.

GENERAL TIPS 2 :::--- Standard Phosphorus Solution, 0.1 mg/mL as Phosphorus: Dissolve exactly 0.4395 g (Note 5) of reagent grade potassium dihydrogen phosphate (KH₂PO₄) in 500 mL of purified water in a 1 L volumetric flask; dilute to volume with purified water and mix thoroughly. Standard Solution: 2 µg Phosphorus per mL: 

OTHERWISE :

Standard phosphate solutions: 22.068 mg of anhydrous KH₂PO₄ was dissolved in distilled water and diluted to 100 mL. Thus, 1mL = 50.3µg PO₄ 3 --P.