Method optimization and validation for the simultaneous determination of arachidonic acid metabolites in exhaled breath condensate by liquid chromatography-electrospray ionization tandem mass spectrometry

We developed an analytical method with on-line clean up and enrichment steps to determine 12 different inflammatory markers in exhaled breath condensate. A specific detection method ensures the unequivocally determination of each analyte at the same run. The method was optimized and validated to achieve a low limit of quantification up to 10 pg/mL each analyte. The precision of the method ranged between 4 and 16%.The presented method should serve as an easy and fast tool to assess the utility of inflammatory markers in exhaled breath condensate to different pulmonary diseases and for several related disciplines in medicine.Different markers in exhaled breath condensate (EBC) have been measured and used for the assessment and monitoring of airway inflammation [1]. Airway inflammation is a consequence of many lung diseases such as asthma, cystic fibrosis or chronic obstructive pulmonary diseases (COPD) [2-4]. In occupational medicine, many problems arise from allergic reactions related with pulmonary diseases, which should be assessed for further medical proceedings. Analysis of EBC is a non invasive method for the measurement of low-volatile inflammatory mediators that are known to be exhaled with the expired water vapour from individuals [5]. In contrast to invasive techniques such as bronchoalveolar lavage and bronchial biopsies, the EBC sample collection can be used repeated times and does not induce an inflammatory response by itself. Easy non-invasive sample collection is an important task in occupational medicine where workers examination issues are often a voluntary matter.Eicosanoids are mediators derived from arachidonic acid and include prostaglandins (PG), isoprostanes and leukotrienes (LT). These eicosanoids were used to try to assess the lung inflammation in patients with pulmonary disease. Some prostaglandins and thromboxane could have proinflammatory or anti-inflammatory properties [6]. Leukotrienes are potent constrictors and proinflammatory mediators