Real-Time Measurement of Trace Elements in Automotive Exhaust

Application of ICP-TOFMS for Real-Time Measurement of Trace Elements in Automotive Exhaust Particulate Matters from Engine Oil Additives

This work demonstrates real-time measurement of trace elements in automobile discharge particles.

Hagino, Hiroyuki et. al.
Analysis of airborne particles from car exhaust or brake wear is of growing interest due to their potential health implications. Many technologies are currently used to monitor organic particles of automotive origin, but the metal content of these particles is not as well characterized, despite being of equal importance. Trace elements within these particles are usually characterized by ICP-MS analysis of digested filter samples.  ICP-MS is the most sensitive method for metals, but the offline analysis of filter experiments measures only the integrated particle flow; variations of particles over time cannot be determined.
Real time monitoring of individual airborne particles is a challenge for ICP-MS because the inductively coupled plasma cannot tolerate the introduction of large amounts of oxygen. In this work, Hagino and co-workers used a Gas Exchange Device (GED) to remove the air fraction from car exhaust and directly sampled the remaining particle beam into an icpTOF instrument.  This setup enabled the correlation of multi-element, single particle data with the engine oil composition and the particle formation during different driving conditions.