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J. Cosmet. Sci., 69, 279–291 ( July/August 2018) 279 Determination of Fluorescent Whitening Agents in Cosmetics and Liquid Detergent by High-Performance Liquid Chromatography with Diode Array Detector in Tandem with Fluorescence Detector YU-XIANG GU, JIN-QIN YANG, SI-YI PAN, LEI WANG, and ZE-LIN ZHOU, Shanghai Institute of Quality Inspection and Technical Research, Shanghai 200233, People’s Republic of China (Y.-X.G., J.-Q.Y., S.-Y.P., L.W., Z.-L.Z.) Accepted for publication August 3, 2018. Synopsis Five distyryl-type fl uorescent whitening agents (FWA85, 210, 220, 351, and 353) were determined in cosmetics and liquid detergent by high-performance liquid chromatography with diode array detector in tandem with fl uorescence detector. The samples were extracted with ultrasound in 33% acetonitrile for 10 minutes and the components were determined by ion-pair chromatography on an MG C18 column. The limits of detection were from 0.01 to 0.1 mg·kg-1 and the limits of quantifi cation were from 0.04 to 0.4 mg·kg-1. The recovery was from 80.7 to 103.3%. A linear relationship was present from 0.10 to 100 μg·ml-1 of FWAs. The protocol was simple, sensitive, selective, and was successfully applied to analyze distyryl-type FWAs in cosmetics and liquid detergent. FWA351 and FWA85 were detected in several samples with the concentrations of 19.4–1,130 mg·kg-1. INTRODUCTION Fluorescent whitening agents (FWAs) belong to the colorless or weakly colored organic compounds in solutions or on substrates, which could enhance the optical impression of whiteness and brightness through absorbing light in the UV range (290–400 nm) and emitting visible blue light (400–480 nm). They are numerous in variety with different structural properties. The main types of FWAs include distyryl-type, benzoxazole-type, pyrazoline-type, and coumarin-type the distyryl-type is the most widely used product. Now FWAs extensively apply in textiles, paper manufacturing, household detergents, plastic products, and cosmetics to eliminate the yellowish cast of white fabrics and increase the whiteness and brightness of products (1–4). Usage of FWAs in detergent could be traced back to the 1940s. In recent years, with the rising demand for the appearance of the products from consumers, application of FWAs Address all correspondence to Yu-Xiang Gu at guyuxiang@aliyun.com.