Capillary electrophoresis - A new tool for ionic analysis of exhaled breath condensate

Exhaled breath condensate has been analyzed for its ionic content by capillary electrophoresis with capacitively coupled contactless conductometric detection. A simple device for collection of small volumes (100-200 mu L) of exhaled breath condensate in less than 2 min was developed. A method for simultaneous determination of inorganic cations, inorganic anions and organic anions from the samples using dual-opposite end injection principle with a short fused silica capillary (35 cm, 50 mu m I.D.) was developed. A background electrolyte composed of 20 mM 2-(N-morpholino)ethanesulfonic acid, 20 mM L-histidine, 30 mu M cetyltrimethylammonium bromide and 2 mM 18-crown-6 was used. The analysis time was less than 3 min with limits of detection reaching low mu M levels for most of the anions and canons. It has been shown that changes of nitrite could be observed in acute inflammation of upper airways and in a person with diagnosed mild chronic obstructive pulmonary disease, while changes of other ions could also be observed. Lactate concentrations could also be monitored and about 4-fold increase of lactate concentration in exhaled breath condensate was determined following an exhaustive cycling exercise. The developed non-invasive sampling of exhaled breath condensate, followed by rapid capillary electrophoretic analysis, could be very useful in lung inflammatory disease screening as well as in monitoring fast metabolic processes such as lactate build-up and removal. (C) 2012 Elsevier B.V. All rights reserved.