Determination of phosphoric acid (H3PO4)

What is phosphoric acid?

Phosphoric acid (CAS No. 7664-38-2) is a strong inorganic acid widely used in many industries for its acidifying, buffering, and antioxidant properties. It is mainly found in industrial beverages, mineral fertilizers, cosmetics, and some technical formulations or cleaning products.

It plays a crucial role in pH control, preservation, chemical stability of formulations, and can also act as a chelating agent or metal stabilizer.

Why measure phosphoric acid?

The dosage of phosphoric acid is essential in various industrial and regulatory contexts:

• Quality control of raw materials and finished products
• Compliance with maximum levels authorized by regulations (EU, FDA, etc.)
• Verification of functional or nutritional claims
• Balancing of formulations (pH, stability, antioxidant action)
• Prevention of deposits, crystallizations or adverse reactions

In the food industry, particularly for soft drinks, this dosage is used to verify the expected acidification and ensure consistent taste. In phosphate fertilizers, it contributes to the characterization of the finished product and compliance with composition standards.

Available analytical methods

The dosage of phosphoric acid can be carried out by different physicochemical methods depending on the matrix:

• Ion exchange chromatography: reference method for complex liquids, waters and multi-component formulations
• UV-Vis spectrophotometry: suitable for simple and clear products
• Acid-base titration: used in stable formulations with high acid content
• ICP-OES (Inductively Coupled Plasma Atomic Emission Spectrometry): for indirect detection via total phosphorus in technical or environmental matrices

Each method is selected based on the type of product, the regulatory thresholds to be respected and the complexity of the matrix to be analyzed.

Affected matrices

Phosphoric acid analysis applies to a wide range of industrial and consumer products:

• Industrial drinks: sodas, concentrated juices, energy drinks
• Phosphorus-based food supplements or nutraceutical formulations
• Phosphate or organo-mineral fertilizers (liquid or granular)
• Cosmetics: peels, scalp care, exfoliating products
• Acidic cleaning products: descalers, industrial solutions
• Technical formulations: solvents, lubricants, surface treatment agents

The analysis is also relevant in quality audits, comparative tests and export batch controls.

Regulatory aspects

Phosphoric acid is authorized as a food additive (E338) in the European Union. Its use is strictly regulated in the food, cosmetics, and environmental sectors. Applicable standards include:

• Regulation (EC) No 1333/2008 on food additives
• Regulation (EC) No 1223/2009 for cosmetics
• Safety data sheets and REACH specifications for technical formulations
• Environmental standards for phosphate discharges into wastewater

Dosage is therefore essential to guarantee consumer safety, compliance with customer specifications and compliance with phosphate content limits.

Why use YesWeLab?

At YesWeLab, we connect you with ISO 17025-accredited partner laboratories specializing in physicochemical and regulatory analysis. Our strengths:

• Selecting the most relevant method for your matrix
• Detailed results, usable for your audits, labeling or regulatory files
• Personalized scientific support according to your product or sector constraints
• Access to our digital platform for simplified management of your requests

Need to analyze phosphoric acid in your products?

YesWeLab helps you master your formulations, validate your regulatory compliance, and strengthen your product quality.
Contact our team for a quick quote or a study tailored to your needs.