Chromatographic methods and sample pretreatment techniques for aldehydes determination in biological, food, and environmental samples

Aldehydes are very reactive carbonyl compounds that are widespread naturally. Aldehydes can be produced in vivo by oxidative reactions and are able to disturb biological functions through binding and modifying biomolecules. Thus, it is necessary to determine their levels in biological samples to estimate their possible adverse effect on human health in addition to their consideration as a biomarker for oxidative stress-related diseases. Furthermore, aldehydes have been found in foodstuffs as by-products of food processing or deterioration and their amounts in food samples were used as an indicator of its quality. Aldehydes also are widely distributed in the environment sourced from the industrial and motor vehicular exhausts and human exposure to them could bring many adverse health effects. From these viewpoints, an effective analytical method for the determination of aldehydes should be essential in various fields including biological, clinical, environmental, and food sciences. Among analytical methodologies, chromatographic determination methods should be suitable tools for the simultaneous determination of wide variety of aldehydes. Derivatization reactions are frequently applied for aldehydes to improve their detection sensitivity as most of them do not possess detectable moiety. Also, derivatization can control their retention behavior on HPLC columns. Moreover, sample pretreatment procedures for aldehydes to modify their high volatility, reactivity, polarity, and inherent instability is vital for their pre-concentration and avoiding matrix effects. In this review, chromatographic determination methods for aldehydes are summarized mainly according to the recent reports with the analytical techniques including the effective extraction and chemical derivatization. Besides, the applications for the chromatographic determination of aldehydes are summarized and significant findings obtained by the application studies are described.