Thelinearrangeofthemethodwasinvestigatedbydetermining calibration curves in the concentration ranges of interest.Recoveries were investigated by adding a methanol calibration solution (containing 1.0nmol for all the aldehydes)to1mLofhumanbloodcontainingknownamountsof aldehydes.Aliquots (1mL) of an aqueous solution containing ethanal, propanal, butanal, pentanal, hexanal and heptanal at concentrations of 0.01-20mM were added to 8-mL vials.The precision of the method was expressed by the relative standard deviation (%, RSD).Triplicate measurements were performed