[Determination of phenol and formaldehyde in resol resins by high performance liquid chromatography]

A high performance liquid chromatographic (HPLC) method was developed for the separation of formaldehyde and phenol from the other components of resol resins. The sample was dissolved in methanol and treated with 2,4-dinitrophenylhydrazine in order that formaldehyde was derivatized to form 2,4-dinitrophenylhydrazone with high UV absorbance. The separation was carried out on a Waters Symmetry C18 column (5 microm, 4.6 mm x 250 mm) with methanol-water (43:57, v/v) as the mobile phase at a flow rate of 0.8 mL/min. The detection wavelength was 270 nm for phenol and 360 nm for the derivative of formaldehyde. The results showed that derivatization had no effect on the determination of phenol. The relative standard deviations (RSDs) of the contents of phenol and formaldehyde were below 5%, the limits of detection (LODs) were below 1 microg/L, and the recoveries were between 96% and 105%. With this method, formaldehyde and phenol in the resol resins can be determined by only one injection. As a result, this method would meet effective control for quality of this kind of resol resins.