High-performance liquid chromatography and capillary electrophoresis: methodological challenges for the determination of biologically relevant low-aliphatic aldehydes in human saliva

Tobacco smoke is involved in the pathogenesis of cardiovascular and respiratory diseases and also has a local toxic effect in the oral cavity. Low-aliphatic aldehydes, such as formaldehyde, acetaldehyde and acrolein, are among the main components of mainstream cigarette smoke and their local noxious and carcinogenic effects in the oral cavity and upper gastrointestinal tract are well-known. Although various studies have been performed so far to determine their content in cigarette smoke, none has included the direct measurement of these compounds in the saliva of smoking and nonsmoking subjects. Thus, in an attempt to verify whether typical chromatographic (high-performance liquid chromatography, HPLC) and/or electrophoretic (capillary electrophoresis, CE) techniques could be reliable methods for determining the levels of these analytes in human saliva, we submitted specimens obtained from a selected population of heavy, moderate, and nonsmoking subjects to HPLC and CE analyses. Both methods showed good reproducibility in terms of migration times and peak height and/or areas and had comparable linearity. Quantitative analyses performed on the specimens investigated evidenced a 3.5-fold increase of low-aliphatic aldehydes in saliva of nonsmoking subjects after they have smoked a single cigarette and a further 2-fold increase of these compounds in saliva of smokers with a daily consumption of 10 or more cigarettes.