Negar Amirhaghian - Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
Azam Samadi - Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
Maryam Khubnasabgafari - Lung and Tuberculosis Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
Vahid Jouyban Gharamaleki - Liver and Gastrointestinal Diseases Research Center and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran

Exhaled breath condensate (EBC) is one of the most accessible biological samples because it contains water vapor and hundreds of different compounds of exo- and endogenous origins in trace concentrations. In addition, EBC analysis is a non-invasive biological sample which is potentially useful for assessing the response to pharmacological therapy. Therefore, it could be as an alternative blood and urine tests [1, 2].In the present study, a simple and sensitive HPLC–Fluorescence method was developed for determination of metoprolol in EBC samples. The separation was carried out on a C18 column (250 × 4.6 mm, 5 μm) by isocratic elution with sodium phosphate buffer (pH 3.8) and acetonitrile (40:60, v/v) containing 0.2% SDS as the mobile phase. Under optimized conditions, the proposed method was successfully applied to determine metoprolol in EBC samples of patients