Gas phase-pollutants, nitric acid (HNO3), sulfur dioxide (SO2), ammonia (NH3) and particulate matter, were collected simultaneously for six months from the Eastern Mediterranean atmosphere (Kucuk Calticak, Antalya) using a "filter pack" system developed in our laboratory. This system is a combination of chemically treated filters for the collection of gaseous ammonia and sulfur dioxide, and Teflon and nylon filters for the collection of particulate matter and gaseous nitric acid, respectively. After pre-treatment, Teflon, nylon and the treated filters were analyzed by ion chromatography (IC) for major ionic species: SO42-, NO3- and Cl-, and by colorimetry for NH4(+) ion. Comparison of the SRM (Standard Reference Material) results with measured concentrations showed a good precision for the IC analyses: 3%, 1% and 2% for Cl-, NO3- and SO42- ions, respectively. Most of the measured parameters were log-normally distributed. Chloride ion had the highest. (4.30 hg m(-3)) and HNO3 had the lowest (0.42 mug m(-3)) concentrations. Total acidity-in the Eastern Mediterranean is controlled by 47.7% HNO3 and 52.8% by H2SO4. Ammonium, nss-SO42- (non-sea salt sulfate) and NO3- did not show a strong correlation, (r(2)=0.4), which means that ammonia is not the major neutralizing species in the Eastern Mediterranean atmosphere.