A mass spectrometric detector has been coupled with carbohydrate high-performance anion-exchange chromatography, by using electrochemical neutralization of the hydroxide eluent and adduct formation with lithium. A very high specificity was obtained with SIM channels, which allowed the separation of coeluting compounds. A full scan channel was also used to record mass spectra from unknown compounds. Carbohydrates extracted from leaves ofwater-stressed poplar were analyzed using HPAEC-PAD and HPAEC-MS. The later method permitted to confirm peak attributions and to identify salicin as a major compound in most samples. Contrasted responses of carbohydrates to drought stress were obtained. Fructose and galactose displayed a higher concentration during stress and recovery whereas glucose content displayed a transient increase in drought treated plants but returned to a control level after re-hydration. The endogenous content of salicin increased during water deficit and continued to rise at the end of the drought treatment. On the whole, HPAECMS and HPAEC-PAD have to be considered as complementary techniques: Classical HPAEC-PAD can be routinely used to quantify carbohydrates, whereas HPAEC-MS offers a higher selectivity and is a tool of choice to elucidate unknown peaks.