engleski

Determination of mass concentrations of chlorides, nitrates and sulphates in the air by ion chromatography

Acid aerosols in ambient air are in the respirable size range and deposit in the lungs airways and alveoli when inhaled. This paper presents the results of chloride, nitrate and sulphate content in respirable particle fraction (PM2.5 - particles with equivalent aerodinamic diameter less than 2.5 mm) of airborne particles in Zagreb air. Samples of respirable particle fraction were collected over 24-hour periods on membrane filters from aproximately 100 m3 of ambient air, at the Northern part of Zagreb during one year period (1st April 1999 - 31st March 2000). After the extraction in an ultrasonic bath (1 hour, 40 °C) the mass content of water soluble chlorides, nitrates and sulphates in the sample were determined by ion chromatography on Dionex DX-120 apparatus with suppressed conductivity detection. Dionex AS 14: 4mm Analytical Column + AG 14: 4mm Guard Column were used. Results show that the mass distributions of pollutants tend to be asymetric and that they could be well described by the lognormal distributions with the following parameters (median ; sg): chlorides (0.27 mg m-3 ; 1.87), nitrates (1.99 mg m-3 ; 2.75) and sulphates (3.97 mg m-3 ; 2.08). The overall anion mass content in the respirable particle fraction accounts 22 %.

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