A new methodology for determination of airborne nanoparticle effective density with the tandem DMA-ELPI based on multiple charging correction

In this work, we propose a method based on simultaneous size-integrated measurements of two particle concentrations (number and lung-deposited surface area, CNC/NSAM), and on the estimation of the average size of potentially inhaled particles obtained by combining these measurements. The proposed method could form part of a practical measurement strategy, as it would use field-portable, commercially available aerosol instruments. In the absence of instruments that provide real-time size-resolved measurements, this original approach can be carried out because the ratio of the particle concentrations is a monotonous function of particle size. Even though the method proposed is less accurate than one that employs traditional instruments such as SMPS, it might nevertheless be used for workplace air monitoring or as a screening tool for detecting the presence of airborne nanoparticles.