How to detect fluorescent brighteners in cosmetics？

When it comes to the detection of fluorescent whitening agents, the first thing everyone thinks of is to use a currency detector to irradiate it, which is the ultraviolet lamp method. Since the principle of the fluorescent whitening agent is that the blue light excited by the ultraviolet light neutralizes the yellow light, it can be judged whether it contains the fluorescent whitening agent by directly irradiating the ultraviolet lamp to see if the object emits blue fluorescence. This method is very simple, and ordinary consumers can also use it, but it also has certain limitations. Because this method can only tell you that the product has a "fluorescence" phenomenon, it cannot prove that the fluorescent whitening agent is definitely added, let alone what is added and what is the content. Of course, it is helpful for ordinary consumers to avoid buying products containing fluorescent substances.

The second method is ultraviolet spectrophotometry, which requires professional equipment. Determine its content by measuring the amount of light absorbed by different fluorescent whitening agents and comparing with standard products. This method can accurately determine the content of fluorescent whitening agent, provided that you know what fluorescent whitening agent is used. The equipment used in this method is cheap and simple to operate, and can be used for product testing in enterprises. However, the cosmetic matrix is very complicated and easily interfered. The detection risk for unknown products is very high and it is not suitable for promotion.

The third method is molecular fluorescence spectrophotometry. The type and content of the fluorescent whitening agent are determined according to the light intensity and wavelength reflected by the fluorescent whitening agent, but the fluorescent whitening agent needs to be separated from the product before the measurement, so it is the same as the second method , Not suitable for cosmetics with complex matrix, more suitable for determining the type of fluorescent whitening agent used in raw materials.

The fourth method is high performance liquid chromatography. After the pre-processed sample is separated by chromatography, it is detected by a suitable detector and accurately quantified according to the corresponding fluorescent whitening agent standard. The detection cost of this method is relatively high, and it is suitable for the accurate quantification of specific fluorescent whitening agents in complex matrices in professional inspection institutions. However, if you use conventional ultraviolet or fluorescent detectors, you will have certain limitations to determine unknown fluorescent whitening agents. Sex. If a mass detector is used, the separation, qualitative and quantitative of the fluorescent whitening agent can be realized at the same time, and the instrument has high sensitivity, which is very suitable for the qualitative confirmation and quantitative analysis of unknown fluorescent whitening agent in complex matrix.

In summary, the probability of cosmetics containing fluorescent whitening agents is extremely low, and even products containing fluorescent whitening agents are not necessarily unsafe. They are safe at normal dosages, and consumers must maintain good health mentality.