[Simultaneous determination of six aldehydes in water-based coatings by high performance liquid chromatography with...

A high performance liquid chromatography method with pre-column derivatization was developed for the simultaneous determination of formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, n-valeraldehyde and p-tolualdehyde in water-based coatings. After ultrasonic extraction with water, the samples were derivatized with 2,4-dinitrophenylhydrazine (2,4-DNPH) in acetonitrile under acidic condition, then filtrated by 0.45 microm organic syringe filters for the determination. Systematic investigation was carried out on the dependence of the derivatization conditions such as the acidity regulator, pH value, reaction temperature, reaction time and other factors. The optimized conditions were as follows: the dilute hydrochloric acid solution as acidity regulator, the pH of the buffer solution of 3, the reaction temperature of 60 degrees C, and the reaction time of 30 min. Under the conditions, a linear relation was achieved in the range of 0.08-2.0 mg/L for the peak area to concentration of the six aldehydes. The detection limits were 0.05-2.50 mg/kg. The recoveries of standard addition at the spiked levels of 2.0, 4.0, 6.0 mg/kg were 87.0%-112.8% with the relative standard deviations (RSDs, n = 6) of 1.12%-9.54%. The results showed that this method has a wide linear range, good precision and accuracy, and it is suitable for the simultaneous determination of the six aldehydes in water-based coatings.