The mass concentrations and content of water-soluble anions (Cl⁻, NO₃⁻, SO₄²⁻) and cations (Na⁺, NH₄⁺, K⁺, Mg²⁺, Ca²⁺) in the PM_2.5 particle fraction were measured, and an investigation of their relationship and their contribution to the total PM_2.5 mass measured was conducted at an urban background site as part of the Croatian monitoring network for air quality located in Rijeka, Croatia. Daily samples of PM_2.5 particle fraction were collected over 2017 on PTFE filters using a low volume sampler Sven Leckel SEQ 47/50. Mass concentrations of the PM_2.5 particle fraction were determined by gravimetry according to the standard HRN EN 12341:2014 (EN 12341:2014). The content of water-soluble inorganic anions and cations were determined using a Thermo Scientific ICS-5000 capillary ion chromatograph. Results show that the annual average PM_2.5 mass concentration was 9.65 μg m^-3 and did not exceed the limit value of 25 μg m^-3 given by the Regulation on the level of pollutants in air (OG No. 117/12). The annual average mass concentrations of ions in PM_2.5 particle fraction was SO₄²⁻> NH₄⁺> NO₃⁻ > Ca²⁺> K⁺> Na⁺> Cl⁻ > Mg²⁺. The contributions of total anion mass and total cation mass to the total PM_2.5 mass were 25.4% and 12.8%, respectively. The acidic property of PM_2.5 was obtained in spring and winter and slightly acidic in summer and autumn. For a prediction of the pollutant sources, we ran a factor analysis which was performed using the statistical packages STATISTICA 13.0. After varimax rotation, the obtained four principal component factors were found to account for 86% of the variance. Factor loadings > 0.7 were considered significant.

质量浓度和含量的水溶性阴离子（CL ^-，NO ₃ ^-，SO ₄ ^2-）和阳离子（Na ⁺，NH ₄ ⁺，K ⁺，Mg的²⁺，钙²⁺）中的PM _2.5颗粒部分在克罗地亚里耶卡的克罗地亚空气质量监测网络的一部分，在城市背景下对它们之间的关系及其对所测得的PM _2.5总量的贡献进行了调查。每日PM _2.5样本2017年，使用小体积采样器Sven Leckel SEQ 47/50在PTFE过滤器上收集了颗粒级分。根据标准HRN EN 12341：2014（EN 12341：2014）通过重量分析法确定PM _2.5颗粒级分的质量浓度。使用Thermo Scientific ICS-5000毛细管离子色谱仪测定水溶性无机阴离子和阳离子的含量。结果表明，PM _2.5的年平均浓度为9.65μgm ^{- 3}，未超过空气污染物水平规定（OG 117/12号）规定的25μgm ^{- 3}的限值。PM _2.5颗粒部分中离子的年平均质量浓度为SO ₄²⁻ > NH ₄ ⁺ > NO ₃ ⁻  > Ca ²⁺ > K ⁺ > Na ⁺ > Cl ⁻ > Mg ²⁺。总阴离子质量和总阳离子质量对总PM _2.5质量的贡献分别为25.4％和12.8％。PM _2.5的酸性是在春季和冬季获得的，而在夏季和秋季则呈弱酸性。为了预测污染物的来源，我们使用统计软件包STATISTICA 13.0进行了因子分析。方差最大旋转后，发现获得的四个主成分因子占方差的86％。因子负载> 0.7被认为是重要的。