Abstract: A method for the determination of N,N-dimethylformamide (DMF) residue in fluorescent brightening agent CBS by reversed-phase high performance liquid chromatography (RP-HPLC) was established. An Ameritech Accurasil C18 column (150 mm×4.6 mm,5 μm) was used with methanol-water as the mobile phase with gradient elution. The flow rate of the mobile phase was 1.0 mL/min and the detection wavelength was 205 nm. The column temperature was 30 ℃ and the injection volume was 5 μL. There was a good linear relationship between the peak area and the concentration of DMF in the range of 0.19~141 mg/L. The recoveries of DMF were 98.4%~107.3% at the spiked levels of 0.2344% and0.4678%. The limit of detection was 0.019%. The relative standard deviation was 1.73%. This method can be used for the determination of DMF in fluorescent brightening agent CBS quickly and accurately.

Key words: fluorescent brightening agent CBS, N,N-dimethylformamide (DMF), residue, reversed-phase high performance liquid chromatography (RP-HPLC)