EC assessment on real samples by Thermal Optical Transmittance method with and without WSOC removal and using different protocol

In this work, results on EC concentrations obtained by the Thermal Optical Transmittance method (TOT) using low-temperature and high-temperature protocols are shown. Analyses were carried out on PM10 samples collected at a heavily polluted urban site (Milan, Italy) during a winter and a summer field campaign. Three thermal protocols were applied, mainly differing for the highest temperature in the inert atmosphere (i.e. 870°C, 650°C, and 580°C). Measurements were carried out on both untreated and water washed samples. The aim was to find out the most suitable protocol to analyse samples collected in heavily polluted areas like the Po Valley, which is one of the main pollution hot-spots in Europe. Attention was focused on the possible EC pre-combustion and on the role of the carbon evolving at high temperature in the He step. The high temperature protocol resulted to be the one minimising possible biases.