Comparison of HPLC and Spectrophotometry Methods on Quantitative Determination of Formaldehyde in Water Based Coatings

Abstract

To explore and compare the reliability of the quantitative determination of formaldehyde content of water based coatings, the high performance liquid chromatography (HPLC) after derivatization to 2.4-dinitrophenylhydazone and UV-VIS spectrophotometry were studied, respectively. HPLC was performed on a C18 column with acetonitrile/water (65/35, V/V) as mobile phase at a flow rate of 1.0 mL/min, and analyses was detected using Photodode Array Detector (DAD) at the wavelength of 360 nm. And formaldehyde was determined with spectrophotometry at 435nm. The result showed the standard curve of formaldehyde by the HPLC method was linear in the range of 0.1-5.0 mg/L (R2=0.9998). The detection limit was 0.96mg/kg, recoveries were ranging from 96.2% to 101.3%. The linear range of formaldehyde by the spectrophotometric method was 0.1～5.0 mg/L (R2=0.9995), and the detection limit was 5.93mg/kg, recoveries were ranging from 98.5% to 105.3%. In conclusion, both the two methods can be used for quantitative analysis of formaldehyde in water based coatings, and the major advantages of HPLC are quick, simple and sensitive.