Determination of solubility in potash

Potassium solubility testing is an analytical method used to determine the proportion of soluble matter in an alkaline solution of KOH (potassium hydroxide) . This test is particularly useful for the chemical characterization of complex organic materials such as plant fibers, natural resins, plant extracts, or bio-based polymers .

It allows us to evaluate the soluble fraction under the action of a strong base and to deduce information on the purity, reactivity or degree of chemical modification of a material.

Principle and analytical method

The method is based on the partial dissolution of the material in a controlled concentration potassium hydroxide solution, followed by a quantitative assessment of the insoluble residue.

Two analytical approaches can be used:

• Gravimetry : direct measurement of mass loss after dissolution and drying of the insoluble residue. This simple and robust method is suitable for natural fibers and polymers.
• Titrimetry : determination of the concentration of species dissolved in the solution after reaction, for a finer chemical evaluation of solubilized compounds.

Temperature, potassium concentration and contact time are strictly controlled to ensure reproducibility of results.

Affected matrices

This test is applicable to a wide range of matrices:

• Natural fibers (linen, hemp, cotton, cellulose, vegetable or animal keratin),
• Natural and bio-based polymers,
• Plant-based resins and glues,
• Extracts of plants rich in lignin or tannins,
• Solid residues from agro-industrial extraction or manufacturing processes.

Analytical and industrial interest

The determination of solubility in potassium hydroxide allows:

• To assess the purity or degree of chemical transformation of a natural material,
• To characterize the lignocellulosic composition (differentiation of soluble and insoluble fractions),
• To identify any chemical or thermal treatments the raw material has undergone,
• To control the quality and consistency of batches in the industrial production of fibers, natural polymers or plant extracts,
• To ensure the conformity of raw materials used in animal nutrition or in the formulation of compound feeds .

Sector applications

This test has applications in various fields:

• Animal nutrition : evaluation of digestibility and soluble alkaline fraction of plant ingredients.
• Agro-industry : control of plant and lignocellulosic by-products.
• Bio-based materials : characterization of natural polymers and biocomposites.
• Cosmetics and phytotherapy : analysis of natural extracts used in formulations.

Further analyses recommended

For a complete characterization of plant or polymeric material, YesWeLab recommends:

• Cellulose and lignin analysis
• Dry matter dosage
• Ash content analysis
• Total protein assay (Kjeldahl)

These additional analyses allow for a thorough evaluation of the physico-chemical composition and the nutritional or functional value of the raw materials studied.

YesWeLab Expertise

At YesWeLab , this test is performed in partnership with ISO 17025 and COFRAC accredited laboratories specializing in physicochemical analysis and the characterization of natural materials.
Our scientific team selects the method best suited to your matrix and your analytical objective (quality, compliance, research).

Thanks to the YesWeLab digital platform , you can order, track and centralize your analyses while benefiting from personalized technical support .