--- type: "WebPage" title: "Determination of propionic acid/propanoic acid (CAS No. 79-09-4) in laboratory" description: "You would like to perform the determination of propionic/propanoic acid (CAS No. 79-09-4) present in your matrices Ensure the conformity, preservation and quality of your products with cutting-edge analytical expertise on propionic/propanoic acid (CAS No. 79-09-4) Propionic acid (or propanoic..." resource: "https://filab.fr/en/our-services/our-analysis-services/chemical-analysis-laboratory/propionic-acid-determination/" tags: ["EN", "pll_695fc4378c384", "Anaïs DECAUX"] timestamp: "2026-01-08T15:47:36Z" published: "2026-01-08T15:47:35Z" language: "en" author: "Laure Durieux" --- # Determination of propionic acid/propanoic acid (CAS No. 79-09-4) in laboratory ## You would like to perform the determination of propionic/propanoic acid (CAS No. 79-09-4) present in your matrices ### Ensure the conformity, preservation and quality of your products with cutting-edge analytical expertise on propionic/propanoic acid (CAS No. 79-09-4) Propionic acid (or propanoic acid) is a key molecule whose analytical control is essential to guarantee patient safety, the [stability of skincare formulations](https://filab.fr/en/sectors-of-activity/health-pharmaceutical-cosmetics/stability-testing-medications-and-active-ingredients.md), and the mechanical properties of [polymer materials](https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory.md). FILAB laboratory provides high-precision assay solutions adapted to the most complex matrices and the strictest regulatory environments (**GMP, ISO, ICH**). ## Specific challenges by sector of activity ### Propionic/propanoic acid analysis services for the pharmaceutical industry In the [Pharmaceutical industry](https://filab.fr/en/sectors-of-activity/analysis-industry-pharmaceuticals.md), propionic acid is used as a precursor in synthesis (particularly for non-steroidal anti-inflammatory drugs such as ibuprofen) or as a preservative. - **Purity control**: [analysis of residual solvents and organic impurities according to **ICH Q3C guidelines**](https://filab.fr/en/sectors-of-activity/health-pharmaceutical-cosmetics/laboratory-analyis-ich-q3c.md). - [**Stability of active ingredients**](https://filab.fr/en/sectors-of-activity/health-pharmaceutical-cosmetics/laboratory-analysis-active-ingredients.md): monitoring of propionic ester degradation. - [**Trace analysis**](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-failures/laboratory-analysis-trace-chemicals.md): precise quantification to ensure the absence of risks. -   ### Propionic/propanoic acid analysis services for cosmetics Used for its antifungal and antimicrobial properties, propionic acid must be precisely dosed to comply with [Cosmetic Regulation (EC) No. 1223/2009](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-nanomaterial/cosmetic-regulation-ce-n1223-2009.md). - **Regulatory compliance**: verification of concentration limits for preservatives. - **Formula integrity**: influence on the acid-base balance (pH) and texture of emulsions. ### Propionic/propanoic acid analysis services for the polymer industry Propionic acid is a key reagent in the manufacture of plastics, particularly **cellulose acetopropionate (CAP)**. - [**Materials characterization**](https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory/laboratory-material-testing/): determination of residual free acid after polymerization. - [**Migration tests**](https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory/plasticizer-migration-study.md): for polymers intended for medical or food contact applications, measurement of propionic acid release in simulants. - **Physicochemical properties**: evaluation of the impact of acid residues on the [viscosity](https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory/viscosity-index-measurement-on-polymer.md) and durability of polymers. ### Our technical ressources for the determination of propionic/propanoic acid (CAS No. 79-09-4) [### GC-MS To identify and quantify propionic acid](https://filab.fr/en/our-technical-resources/laboratory-analysis-gcms.md) [### GC-FID Separation of volatile fatty acids (VFAs) and precise identification](https://filab.fr/en/our-technical-resources/gas-chromatography-analysis-lab-gc/gc-fid-analysis-laboratory.md) [### HPLC-UV Used for less volatile matrices or on simple aqueous solutions.](https://filab.fr/en/our-technical-resources/laboratory-analysis-uplc.md) [### IC For the selective determination of propionate ions in aqueous or complex matrices](https://filab.fr/en/our-technical-resources/laboratory-ion-chromatography.md) ## The FILAB laboratory assists you in the determination of propionic/propanoic acid (CAS No. 79-09-4) **Securing** the shelf life **Avoid** disputes related to odors or residual impurities **Optimizing** polymerization processes **Certify** compliance with international monographs ## Why choose FILAB for the determination of propionic/propanoic acid (CAS No. 79-09-4)? For over ten years, the FILAB laboratory has developed extensive expertise in [chemical analysis](https://filab.fr/en/our-services/our-analysis-services/chemical-analysis-laboratory.md). Our laboratory boasts [state-of-the-art analytical equipment](https://filab.fr/en/our-technical-resources.md) and highly skilled personnel to provide services that meet your compliance requirements for the analysis of propionic/propanoic acid (CAS No. 79-09-4). ## FAQ What are the limits of quantification (LOQ) for propionic acid? Our quantification limits are tailored to your regulatory requirements. Using **GC-MS** (Gas Chromatography-Mass Spectrometry), we can achieve levels on the order of **ppm (mg/kg)**, or even lower depending on the complexity of the matrix. These levels are essential for detecting residual impurities in active pharmaceutical ingredients (APIs) or for migration testing in polymers. Why choose GC-MS over HPLC for this molecule? Propionic acid is a naturally volatile, short-chain fatty acid. Gas Chromatography (GC) is therefore the reference technique: - **Selectivity**: it allows for the precise differentiation of propionic acid from acetic or butyric acid. - **Sensitivity**: coupling with mass spectrometry (MS) enables definitive identification of the molecule, eliminating any risk of false positives in complex matrices such as filled polymers or cosmetic creams. How do you manage the dosage of propionic acid in solid polymers? For polymers (e.g., cellulose acetopropionate), we generally use the **Headspace technique** coupled with GC. The sample is heated in a sealed vial to release residual acid in gaseous form before analysis. This avoids dissolving the polymer in solvents that could interfere with the analysis or degrade the column. Are your methods compliant with ICH standards? Yes. For the pharmaceutical industry, we develop and validate our methods according to **ICH Q2(R1)** guidelines (specificity, linearity, accuracy, precision). We also ensure compliance with **ICH Q3C** guidelines regarding residual solvents and impurities. What is the impact of incorrect dosage in a cosmetic formulation? An imprecise dosage presents two risks: - **Chemical instability**: propionic acid strongly influences pH. A variation can lead to the denaturation of other ingredients or the separation of an emulsion. - **Sensory risk**: due to its very strong organic odor, a slight overdose can alter the olfactory profile of your finished product, even in the presence of fragrances. How to obtain a quote for propionic/propanoic acid testing? To get a quote quickly (within 24-48 hours), please contact our sales team at the following address : [contact@filab.fr ](https://filab.fr/contact.md)