Phosphate Assay 磷酸盐检测

1. 10% Magnesium Nitrate in ethanol.
2. 1 M HCl.
3. 10% Ascorbic Acid (1 gm/10 ml).
4. Ammonium Molybdate, .42% in 1 N Sulphuric Acid
   (.42 gm 2.66 ml c/H₂SO₄ made up into 100 ml)

1. Weigh 0.5 mg LPS into Pyrex tube.
2. Add 0.05 ml 10% Magnesium Nitrate in ethanol.
3. Evaporate to dryness on flame.
4. Cool. Add 0.3 ml 1 N HCl. Heat at 100^oC for 15 min. in a boiling water bath.
5. Add 0.7 ml Ascorbic/Molybdate (1 part to 6 parts freshly mixed).
6. Keep at 45^oC for 20 min.
7. Read absorbance at 820 nm against reagent blank. (absorbence of 0.240 for 0.01 ?mol phosphate).
   * Ascorbic Acid is stable at 2 - 4^oC for approx.
   7 weeks.