Simple and sensitive determination of low‐molecular‐mass aromatic aldehydes in swimming pool water by LC‐diode array detector

This work reports the development of a simple method for the quantitative determination of aromatic and aliphatic low‐molecular‐mass aldehydes (LMMAs) as disinfection by‐products (DBPs) in indoor swimming pool waters after chlorination with a simplified SPE sample treatment. The method is based on the continuous in situ derivatization/preconcentration of the aldehydes with 2,4‐dinitrophenylhydrazine (DNPH) on a Lichrolut EN column in the presence of β‐CD. After elution, the 2,4‐dinitrophenylhydrazine derivatives were separated on an RP‐C 18 analytical column using gradient of ACN–water at 60–80%. The optimized sample treatment described here allowed the direct analysis of large volumes of water in order to improve the sensitivity of the method; LODs in the 60–120 ng/L range were achieved for aromatic LMMAs by using a volume of 50 mL of water, precision being 7.5% or better at a concentration level of 5 μg/L. These results indicate that the ensuing method is a useful choice for the determination of LMMAs in water samples that provides better results than reported LC alternatives in terms of the LOD (except for MS/MS detection), sample requirements for analysis and cost.