Using UV Spectroscopy For Toxicology And Quality Testing In Cosmetics

INTRODUCTION

The cosmetics market is now considered an international superpower, offering countless options. When faced with all those choices, consumers use product quality and safety to determine their spending. Therefore, for manufacturers, quality control is not only a legal issue but also a guarantee of reputation for consumers.

Chemical analysis is often used to ensure both the purity and quality of cosmetics. Spectroscopic techniques provide powerful tools for cosmetic ingredient analysis, contaminant detection, and product formulation verification. Spectroscopy does not require complicated sample preparation steps, does not destroy the analysis sample, and gives accurate analysis results in a fast time to help improve efficiency. This application note explores the application of spectroscopy in toxicology and quality testing in the cosmetics industry.

METHODS AND APPLICATIONS

This application will collect UV and visible light absorption spectra of cosmetics. From the absorption spectrum of the sample, a lot of information about the analyzed sample will be revealed, including chemical composition, and concentration of substances... with high qualitative and quantitative properties.

From absorption spectroscopy combined with other algorithms, this application can completely help manufacturers quantify the concentration of dyes, preservatives, and UV filters in cosmetics. Identify impurities and evaluate product stability.

Specifically, the application of UV-Vis absorption spectroscopy can help manufacturers:

Toxicology Assessment Using Spectroscopy

• Identification of Harmful Substances: Spectroscopy helps identify banned or harmful substances (e.g., parabens, heavy metals) beyond permissible limits.
• Allergen Detection: UV-Vis and MS can detect allergenic compounds (e.g., fragrances, preservatives) to ensure compliance with regulatory limits.
• Quantitative Analysis: Provides accurate quantification of active ingredients and contaminants, ensuring products meet safety standards.

Quality Testing and Authentication

• Counterfeit Detection: Identifies counterfeit products by analyzing their chemical composition against genuine products.
• Stability Testing: Monitors changes in product color or composition due to environmental factors (e.g., light exposure).

A typical practical example of applying UV-Vis spectroscopy to analyze Methyl paraben in cosmetics. It is the most frequently used antibacterial preservative in cosmetics and flavoring agents. Methyl paraben is odorless, colorless small crystals or white crystalline powder freely soluble in alcohol, methanol, acetone, and ether. Due to its broad antibacterial spectrum with relatively low toxicity, good stability, and non-volatility, parabens are often used as preservatives to prevent the alteration and degradation of cosmetics, pharmaceuticals, and foods from contamination. microorganisms and fungi, while protecting consumers.

Some parabens with reported uses are used in products that can be accidentally ingested (e.g., Methyl paraben at up to 0.35% in lipstick), used near areas of contact with eyes (e.g. Methyl paraben up to 0.8% in mascara), contact with mucous membranes (e.g. Methyl paraben up to 0.5% in bath oils, tablets, and salves) or in children's products (e.g. Methyl paraben at up to 0.4% in children's lotions, oils and creams). The upper limit of mass percentage of single ester is 0.4% and the upper limit of mixed ester is 0.8%. The European Economic Community (EEC) Directive states that parabens are allowed at concentrations of up to 0.8% in cosmetics, with a maximum individual concentration of 0.4% (w/w). , expressed as phyroxybenzoic acid.

However, Methyl paraben can cause side effects for consumers and change the sensory qualities of cosmetics. Studies show that paraben use can cause cancer, genotoxicity, and breast cancer. Paraben is also believed to have adverse effects on men as it can reduce fertility, cause infertility, and cause skin cancers such as melanoma, melanoma, and skin cancer. Therefore, the concentration of preservatives as well as the possibility of consuming these substances during the opening and closing of the sample must be calculated to ensure user safety.

Figure 1: Absorbance spectrum of Methyl paraben

The results of Figure 1 shows that the maximum absorption peak of methyl paraben at wavelength 254 nm is clearly shown for each different concentration. Combined with the linearity between intensity at a specific wavelength and the concentration of the compound to be analyzed, it is possible to determine the percentage concentration of methyl paraben in cosmetics as follows:

All products surveyed above ensure the prescribed methyl paraben content. The above survey also publicly revealed that the accuracy of the UV-Vis spectroscopy method is 0.99, the repeatability is very high at 96% and the SD is very small.

From these results, manufacturers can completely trust the method of using UV-Vis spectroscopy to test the toxicity and quality of cosmetics.

BUILD SYSTEM

INTINS can provide a complete system for this application. The Ocean SR4 UV-Vis spectrometer is a high-performance spectrometer with high-speed spectrum acquisition and low signal-to-noise ratio for a variety of applications. The device has a compact design, wavelength range from 190-1100 nm with slit width options from 5 μm to 200 μm. This versatile spectrometer is anchored by a 3648-element CCD array detector and powerful electronics to perform capable measurements online or in the laboratory. Robust thermal wavelength stability and low stray light performance ensure reliable, reproducible results, even in challenging industrial environments. Diverse communication methods: USB, Ethernet, RS232.

At the same time, our company will also provide a full of different accompanying products to create a full absorption measurement system for this application such as light source, fiber, and sample holder... If you have any questions or need any further detailed information, please contact us.

CONCLUSION

UV-Vis spectroscopy is indispensable in ensuring the safety, quality, and compliance of cosmetic products. By allowing rapid and non-destructive analysis, spectroscopy improves efficiency in toxicological assessments and quality control processes. Implementing these techniques allows cosmetics manufacturers to maintain regulatory standards, protect consumer health, and maintain brand integrity.

For more information on applying spectroscopy to cosmetics testing or to discuss specific analytical challenges, please contact our technical support team.