a long time ago, people mainly relied on traditional bleaching and bluing techniques to make white items, but they gave people an old-fashioned feel. the use of fluorescent whitening agents has a whitening effect that is unmatched by blue-whitening and chemical bleaching. since then, the application scope of fluorescent whitening agents has become more and more extensive, starting from the textile industry and gradually developing into food and food contact materials. , cosmetics, paper products, detergents and other industries
1 application in food industry
applications in food
in addition to its obvious whitening effect, fluorescent whitening agents also have certain preservation and antiseptic effects. fluorescent whitening agents are chemical products and are not allowed to be used in food. however, there are currently many unscrupulous vendors who illegally use them in edible fungi and other foods in order to whiten and preserve the effect. this behavior will cause potential harm to the human body. , there are security risks [16]. at present, there is no national standard method for the detection of fluorescent whitening agents in food in my country. there are only the ministry of agriculture standard ny/t 1257-2006 “detection of fluorescent substances in edible fungi” [44] and the import and export industry standard sn/t 4396. -2015 “determination of fluorescent whitening agent 85, fluorescent whitening agent 71 and fluorescent whitening agent 113 in exported foods by liquid chromatography-mass spectrometry/mass spectrometry” [45]. the former uses ultraviolet light irradiation observation method, which can only conduct qualitative analysis of samples and cannot quantitatively detect; the latter can quantitatively detect, but it only targets three kinds of fluorescent whitening agents in some foods, which is not comprehensive enough.
applications in food contact materials
food contact materials (fcm) are the collective name for all materials and products that come into contact with food, such as food packaging, food utensils, and auxiliary materials, equipment, and tools used for processing and preparing food. the types are paper packaging and plastic packaging. mostly. due to the increasing shortage of paper raw material resources, the proportion of waste paper recycling is increasing year by year. according to surveys, about 80% (by weight) of plastic products are colored, and the largest number of them are white plastic products. the use of fluorescent whitening agents in food contact materials can increase the whiteness and brightness of the product and improve the appearance performance of fcm.
2 application in cosmetics industry
the use of optical brighteners is not explicitly prohibited in the hygienic regulations for daily skin care cosmetics, facial masks and other products, and no relevant standard testing methods have been issued. in order to improve skin whiteness and achieve whitening effects, some cosmetics manufacturers add fwas to cosmetics. for example, some unscrupulous manufacturers maliciously add a large amount of fluorescent whitening agents to whitening masks to give consumers an instant whitening effect, but this also brings potential risks to human health.
3 applications in the textile industry
fluorescent whitening agents were first used in the textile industry. they are transferred to fabrics through different dyeing methods and reflect visible light under ultraviolet light sources, making them white and bright. the function of fwas is not only to whiten but also to brighten light-colored fabrics. textiles treated with fwas not only improve their appearance, quality and grade, but also enhance their commercial value. as a result, the consumption of fwas is increasing.
4 application in sanitary products industry
sanitary napkins are sanitary products that are closely related to women’s health. now it is found that some companies add fluorescent whitening agents without authorization during the production process for the purpose of whitening. even if fwas are not added during the production process, if the quality of the raw materials if the control is not strict or in order to reduce costs, paper pulp containing fwas will be used, resulting in sanitary napkins containing fwas. at present, some media have exposed the presence of varying amounts of fluorescent whitening agents in sanitary napkins of different brands. however, the national standard gb/t 8939-2008 “sanitary napkins (including sanitary pads)” does not mention the fluorescent whitening agent in sanitary napkins. white agent, so both its limit and detection method are in a blank state [46]. now most sanitary napkins are tested using gb/t 27741-2011 “determination of migrating fluorescent whitening agents in paper and paperboard” as the reference standard, but whether it is suitable for the detection of fluorescent whitening agents in sanitary napkins remains to be seen. discuss.
5 application in detergent industry
in recent years, as consumers have increased their requirements for the appearance, quality and hygiene of laundry products, the role of fluorescent whitening agents in laundry products has become more and more important, because textiles will gradually turn yellow during use. during the washing process, the fluorescent whitening agent in the washing products will be adsorbed to the fabric fibers. the blue-violet fluorescence emitted after absorbing ultraviolet light will compensate for the yellow light of the fibers, making the washed white textiles visually return to white and bright. status, leading people to think that detergents containing optical brighteners have better effects than detergents without optical brighteners. in my country, bistriazine amino stilbene and distyryl biphenyl fluorescent whitening agents are allowed to be added to clothing detergents, but there is no maximum usage limit.
6 applications in paper products industry
an important quality indicator judged by the paper products industry is whiteness. in the past, methods such as chlorine bleaching and adding blue dyes or pigments were mainly used to produce whiter paper products. however, the visual effect of this paper product still showed a yellowish and gray state, and people found that in pursuit of higher whiteness, using strong bleaching methods will damage the pulp fiber strength. the use of fwas not only makes paper products brighter in color, but also does not cause more chemical losses to the pulp. it is also easy to use, uses less amount, and achieves benefits that other bleaching methods cannot achieve.to achieve the desired effect. the fluorescent whitening agents currently used in the paper products industry are mainly bistriazine amino stilbene type fluorescent whitening agents. fwas are not only used in ordinary paper, but also in some special paper products. for example, in the cigarette industry, fluorescent whitening agents abp and vbl are mainly used to whiten filter forming paper and tipping paper.