Analysis of lower aliphatic aldehydes in water by micellar electrokinetic chromatography with derivatization to 2,4-dinitrophenylhydrazones

The analysis of lower aliphatic aldehydes in water following derivatization to 2,4‐dinitrophenylhydrazones, was investigated by micellar electrokinetic chromatography (MEKC). The effects of the buffer pH and acetonitrile addition on the separation were investigated. Under optimized conditions the 2,4‐dinitrophenylhydrazine (DNPH) reagent was completely separated from four DNPH derivatized aldehydes with high separation efficiency. DNPH‐formaldehyde and DNPH‐acetaldehyde were also completely separated from one another. Their relative standard deviation of migration times and peak areas were within 1.0% and 3.3%, respectively. The reproducibility of peak areas in this MEKC analysis was as good as that of high‐performance liquid chromatography (HPLC) analysis with the same derivatization method. The recovery values from tap and river water were in the range of 97–102%. The detection limits of formaldehyde and acetaldehyde were 0.05 mg/L and 0.08 mg/L respectively.