Specific H⁺ level is crucial for accurate phosphate quantification using ascorbate as a reductant.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Biogeochemistry

Background:

• Phosphate (PO43-) is essential for cellular metabolism and ecosystem dynamics.
• Accurate monitoring of phosphate levels is vital for assessing ecosystem health.
• Previous methods for phosphate quantification lacked optimal conditions for stability and accuracy.

Purpose of the Study:

• To identify key factors for precise phosphate (PO43-) quantification.
• To optimize the formation and stability of the molybdenum blue complex for phosphate analysis.
• To evaluate the applicability of the optimized method for plant and soil samples and the effect of Azotobacter.

Main Methods:

• Investigated the role of H+ concentration in molybdenum blue complex formation using ammonium molybdate and ascorbic acid.
• Determined optimal concentrations of ammonium molybdate and ascorbic acid.
• Assessed the stability of the molybdenum blue complex under varying H+ levels.
• Evaluated the interference of antimony (Sb) and the applicability to plant and soil samples.

Main Results:

• Optimal molybdenum blue complex formation and stability were achieved with 8-12 mmol H+ in a 3 ml reaction mixture.
• Ideal reagent concentrations were identified as 3% ammonium molybdate, 0.1% ascorbic acid, and 5 M H2SO4 in a 1:1:1 ratio.
• Antimony (Sb) was found to inhibit molybdenum blue formation.
• The optimized protocol proved effective for plant and soil phosphate analysis.
• Azotobacter demonstrated potential to increase phosphate levels in wheat.

Conclusions:

• Established an optimized protocol for accurate phosphate (PO43-) quantification using the molybdenum blue method.
• The method is stable, sensitive, and applicable to diverse environmental samples (plants, soils).
• Azotobacter shows promise for enhancing phosphate availability in agricultural systems.