Low level determination of formaldehyde in water by high-performance liquid chromatography

Abstract

Low levels of formaldehyde in water were determined by derivatization with 2,4-dinitrophenylhydrazine at an optimized pH (1.5–2.5), solid-phase extraction with C₁₈ adsorption cartridges and analysis by reversed-phase high-performance liquid chromatography with ultraviolet detection. A novel procedure for the removal of formaldehyde present as an impurity in blank water was responsible for lowering the detection limit to 0.1 µg l^–1 for a 200 ml sample. A strong anion-exchange resin, in the hydrogen sulfite form, was used to adsorb formaldehyde and any other aldehyde impurities present in blank water. The use of C₁₈ adsorption cartridges also minimized background effects. The recovery of C₁—C₃ aldehydes spiked into purified blank water was 83–93% with a relative standard deviation of 1.4–6.4%.