Abstract: A novel method was developed for trace analysis of aliphatic aldehydes and ketones in water-based adhesive based on 2,4-dinitrophenylhydrazine (DNPH) direct derivatization-1-butyl-3-methylimidazolium hexafluorophosphate (［BMIM］PF6) preconcentration coupled with high performance liquid chromatography (HPLC). The dispersive water-based adhesive emulsion directly reacted with 80 mg/L DNPH solution containing 0.44 mol/L phosphoric acid at 40 ℃ for 18 min. After centrifuging, 0.5 mL ［BMIM］PF6 was added to extract the derivatives at 30 ℃. The ionic liquid (IL) phase was filtered and then analyzed by HPLC. The separation was achieved by using a Dionex Acclaim Explosive E2 column (250 mm×4.6 mm, 5 μm) under the gradient elution with acetonitrile and water as mobile phases at the flow rate of 1.2 mL/min. The column temperature was 35 ℃, and the detection wavelength was 365 nm. The results showed that the limits of detection (LODs) were 0.022~0.221 mg/kg, and the limits of quantification (LOQs) were 0.073~0.738 mg/kg. The relative standard deviations (RSDs) were in the range of 3.5%~7.3%, and the recoveries were 84.0%~102.5% for 8 aliphatic aldehydes and ketones. Compared with solvent extraction, the established method has the advantages of lower LOD and LOQ, and is more stable and precise. This method is practical for the determination of aliphatic aldehydes and ketones in water-based adhesives.

Key words: aliphatic aldehydes and ketones, high performance liquid chromatography (HPLC), ionic liquid gathering, water-based adhesive, direct derivatization