Particulate matter belongs to a group of major air pollutants with lasting effects on human health and the environment. They appear in different sizes, forms, concentrations and compositions as a result of various natural and anthropogenic activities. Due to its variable chemical composition, particulate matter is also a challenge in chemical analysis and in determining the source of their emission. Therefore, large emphasis is placed on them today. In this thesis, carbon analysis was performed on the PM1 fraction of particulate matter, which is still insufficiently researched in contrast to PM10 and PM2.5 fractions. The goal of this research was to introduce the new Eusaar 2 protocol and compare the results obtained by analysing the carbon in the particulate matter of the PM1 fraction by means of thermal optical transmission (TOT) with those obtained by Quartz protocol, which has so far been used as standard protocol in Croatia. Validation of the method for determination of mass concentrations of the elemental carbon (EC) and organic carbon (OC) in particulate matter was carried out by TOT method according to the newly introduced temperature protocol Eusaar 2. Then, carbon analysis was performed on the samples collected during the period 1 Jan – 28 Feb 2018 on the background urban metering station located in the yard of the Institute for Medical Research and Occupational Medicine. By comparing the results of carbon analysis, it was concluded that there were statistically significant differences in the concentrations of OC and EC, whereas differences in average total carbon (TC) concentrations obtained by mentioned protocols are not statistically significant. The measured EC averages, according to the Eusaar 2 protocol, were statistically significantly higher than the values measured according to the Quartz protocol, precisely because of the differences in the temperature programs under which the analyses take place. From the comparison of the average monthly PM1 values for the two-month period at IMROH, it is concluded that they were statistically significantly higher during the second month compared to the first month.