LOW-LEVEL DETERMINATION OF FORMALDEHYDE IN WATER BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

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 mug 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%.