Fluorescent whitening agents （FWAs） are chemical additives that exhibit remarkable whitening effects and have been widely used in the production of detergents, paper, textiles, plastics, and coatings. The production and use of FWAs spans more than 60 years in China； however, the occurrence characteristics of FWAs in environmental water remain unknown. Therefore, a solid phase extraction-ultrahigh performance liquid chromatography-triple quadrupole mass spectrometry （HPLC-MS/MS） method for the trace determination of 11 non-ionic FWAs in surface water was developed. On this basis, the occurrence characteristics and potential ecological risks of these 11 non-ionic FWAs in the Shijiazhuang section of Hutuo River Basin were revealed. The results demonstrated good linear relationships between concentrations ranging from 0.10 ng·L-1 to 50.00 ng·L-1, with correlation coefficients （R2） exceeding 0.99 for all 11 FWAs tested. The limits of detection （LODs） ranged from 0.008 ng·L-1 to 1.00 ng·L-1, while the limits of quantification （LOQs） ranged from 0.01 ng·L-1 to 5.00 ng·L-1. The recoveries were within the range of 55.1%-105.0%, with intra-day relative standard deviations （RSDs） and inter-day RSDs ranging from 1.3%-16.1% and from 1.5%-16.8%, respectively. The concentrations were observed to be at ng·L-1 levels in Hutuo River, with total FWA concentrations reaching up to 182.25 ng·L-1. The concentration of FWAs showed the spatial distribution pattern of water source protection zone>exploitation and utilization zone>reservation zone>buffer zone； especially in 7A, the highest FWAs concentrations were at 35.92 ng·L-1. FWA199 and OB-2 were classified as medium-to-high risk level substances based on their ecological risk quotient values （RQs）, and RQsum > l were obtained from all samples indicating potential risks posed by these FWAs at each sampling site.
Keywords: ecological risk assessment; fluorescent whitening agents（FWAs）; solid phase extraction-high performance liquid chromatography-triple quadrupole mass spectrometry; spatial distribution characteristics; surface water.