Oxalic acid assay

What is oxalic acid?

Oxalic acid is an organic acid naturally present in many plants, including spinach, rhubarb, chard, and beetroot. It is also common in concentrated plant extracts and some dietary supplement formulations.

At high doses, it can bind to minerals such as calcium or magnesium, forming insoluble oxalates. These compounds can reduce the bioavailability of nutrients or promote the formation of kidney stones. Therefore, its dosage is essential for nutritional quality and food safety.

Why analyze oxalic acid?

The measurement of oxalic acids allows us to:

• Check the oxalate content in plant products intended for human or animal consumption
• Optimizing nutraceutical or phytotherapeutic formulations
• Securing plant-rich products in specific diets (low in oxalates)
• Evaluating the quality of plant extracts for technical or cosmetic applications
• Meeting regulatory or commercial expectations related to nutritional labeling or export

Available analytical methods

Oxalic acid is usually measured by:

• HPLC (high-performance liquid chromatography): the reference method for food and plant matrices
• LC-MS (liquid chromatography coupled with mass spectrometry): for sensitive analysis in complex matrices or at low concentrations

These techniques allow for reliable, reproducible quantification, adapted to the standards of the agri-food, nutraceutical and cosmetic industries.

Matrices involved

• Plant extracts (powders, liquids, capsules)
• Leafy vegetables (spinach, chard, rhubarb)
• Processed products: plant-based juices, smoothies, fortified foods
• Nutritional formulations and dietary supplements
• Animal feed (forages, premixes)
• Plant or agricultural raw materials

A standardized extraction is performed prior to the analysis to ensure the representativeness of the results.

Quality and regulatory aspects

Although oxalic acid is not subject to a uniform regulatory limit in Europe, its dosage is:

• Recommended for products intended for people at risk (kidney stones, oxaluria)
• Required for quality certification or export processes
• Relevant in the valorization of ingredients with low oxalate content
• Incorporated into targeted formulations (specific diets, kidney health)

It constitutes a strategic quality control parameter in the plant and nutraceutical sectors.

Why use YesWeLab?

YesWeLab centralizes the best analytical expertise for you through a network of partner laboratories accredited to ISO 17025 or COFRAC, selected according to your technical and regulatory constraints.

Our commitments:

• Guidance towards the method best suited to your matrix
• Scientific support from our experts
• Track your requests via our secure digital platform
• Delivery of clear and actionable reports

Need a reliable oxalic acid assay?

Contact our team now or request a quote online to schedule your analysis as soon as possible.

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• Phytic acid assay
• Coumarin dosage