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 found primarily in industrial beverages, mineral fertilizers, cosmetics, and some technical formulations and 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?

Phosphoric acid dosage is essential in various industrial and regulatory contexts:

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

In the food industry, particularly in soft drinks, this measurement allows for verification of the expected acidification and ensures a consistent taste. In phosphate fertilizers, it contributes to the characterization of the finished product and compliance with composition standards.

Available analytical methods

Phosphoric acid can be determined using different physicochemical methods depending on the matrix:

• Ion chromatography (ion exchange chromatography): the reference method for complex liquids, waters, and multicomponent 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 is applicable to a wide range of industrial and consumer products:

• Industrial beverages: sodas, concentrated juices, energy drinks
• Phosphorus-based dietary supplements or nutraceutical formulations
• Phosphate or organo-mineral fertilizers (liquid or granular)
• Cosmetics: peels, scalp treatments, 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 on cosmetics
• Safety data sheets and REACH specifications for technical formulations
• Environmental standards for phosphate discharges in wastewater

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

Why use YesWeLab?

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

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

Need to analyze the phosphoric acid in your products?

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