Dosage of sodium polyacrylate (SAP)

Sodium polyacrylate analysis allows for the evaluation of the presence, purity, or concentration of this superabsorbent polymer in finished products, packaging, and composite materials. This polymer, often abbreviated SAP (Super Absorbent Polymer), is widely used in industry for its exceptional ability to absorb and retain several hundred times its weight in water.

The analysis of sodium polyacrylate is carried out by selective extraction gravimetric or assay (GC-MS or LC-MS) depending on the nature of the product and the level of precision expected.

Sodium polyacrylate: a superabsorbent polymer

Sodium polyacrylate is a synthetic polymer obtained by polymerizing neutralized acrylic acid with sodium. Its three-dimensional lattice structure gives it a strong absorption capacity, forming a gel when it comes into contact with water or aqueous fluids.

This polymer is used in many industrial applications:

• hygiene products (diapers, absorbent pads, medical incontinence products),
• absorbent packaging for fresh produce,
• agricultural soil additives (hydrogels),
• water retention agents in polymer materials,
• Detergent products, powders and technical formulations.

Due to its chemical properties and interaction with aqueous media, analytical control of sodium polyacrylate is essential to ensure compliance and safe use of finished products.

Objectives and importance of sodium polyacrylate assay

The dosage of sodium polyacrylate allows us to:

• verify the conformity of materials containing superabsorbent polymers,
• to control the amount of SAP incorporated into hygiene products or packaging,
• evaluate the absorption performance and stability of the polymer,
• to ensure chemical compatibility with other components (plasticizers, solvents, mineral fillers),
• monitor the migration or degradation of the polymer in materials subjected to high storage or temperature conditions.

This analysis applies to various matrices:

• synthetic polymers and copolymers,
• plastic films, absorbent sheets and gels,
• hygiene products or technical textiles,
• samples of food or pharmaceutical packaging,
• laboratory formulations or industrial prototypes.
• Analytical methods used

The analysis of sodium polyacrylate relies on several complementary approaches, chosen according to the type of sample:

• Selective extraction and gravimetric assay : the method consists of isolating the polymer by selective solubilization, then determining its content by weighing after drying.
• Gas chromatography-MS : used to identify residual monomers (acrylic acid, sodium acrylate) and polymer degradation products.
• Liquid chromatography (LC-MS) : suitable for complex matrices and formulations containing hydrophilic polymers.
• Infrared spectroscopy (FTIR) : used to confirm the chemical structure of the polymer and to check for the absence of organic impurities or non-compliant additives.

YesWeLab selects the most appropriate method based on the matrix, the expected concentration and the quality control objectives.

For a complete analysis of polymer materials, this service can be combined with acrylic acid assay, styrene assay , or FTIR analysis of polymers.

Industrial and regulatory applications

The dosage of sodium polyacrylate is particularly important in sectors where the safety and quality of absorbent materials are essential:

• Food packaging : SAP is used in absorbent pads placed under fresh produce to limit moisture. Analysis verifies the absence of migration into the food, in accordance with Regulation (EU) No 10/2011 on plastic materials intended to come into contact with food.
• Cosmetics and hygiene : superabsorbent polymers must meet strict purity and biocompatibility requirements. Dosage testing allows for batch control and prevents the release of residual monomers.
• Technical materials and polymers : in industrial applications (adhesives, paints, technical hydrogels), the characterization of SAP guarantees absorption performance and compatibility with other additives.
• Environment and agriculture : Polyacrylates are used as water retention agents in soils. Their concentration allows for the assessment of their degradability and environmental impact.

The analysis is part of a broader control plan, including bisphenol A assay, formaldehyde assay and thermogravimetric analysis (TGA) , to characterize the composition and stability of the materials.

Carrying out analyses at YesWeLab

YesWeLab entrusts the analysis of sodium polyacrylate to partner laboratories specializing in the analysis of polymers and complex materials. These laboratories have high-precision chromatographic and spectroscopic equipment, guaranteeing the reliability and sensitivity of the results.

Analyses are conducted in accordance with ISO 17025 and internally validated protocols, ensuring complete traceability of samples and analytical data.

The YesWeLab scientific team assists each client in choosing the methods best suited to their industrial needs, whether it be production control, material characterization or regulatory validation.

Thanks to the YesWeLab digital platform, requesting quotes, tracking samples and receiving analytical reports are simplified and centralized.

Since 2020, YesWeLab has been collaborating with the packaging, polymer, hygiene and chemical industries to ensure the compliance and performance of their technical materials.

Technical data

• Methods: Extraction, gravimetry, GC-MS, LC-MS, FTIR
• Expertise: Physicochemical
• Business sectors: Packaging, polymers, hygiene, environment
• Measured parameters: Sodium polyacrylate (SAP) content, residual monomers
• Normative references: ISO 17025, Regulation (EU) No 10/2011

For any specific request, contact our team to obtain a personalized quote and analytical advice tailored to your materials or formulations.