Measurement of Water Soluble Organic Carbon in Particulate Matter 2.5

Introduction

Atmospheric particulate matter 2.5 (PM_2.5) is composed of primary particles emitted directly into the atmosphere by a source, and secondary particles generated by chemical reactions in the atmosphere. PM_2.5 describes fine particles of 2.5 μm or smaller in diameter that some fear may affect the respiratory system and circulatory system. In 2009, governmental environmental standards on fine particulate matter were established in Japan. Since their establishment, findings related to sources of fine particulate matter and mechanisms of secondary particulate generation have been deliberated and control measures discussed. Particular emphasis has been placed on measurements for the concentration of water soluble organic carbon (WSOC) in PM_2.5, which is linked to mechanisms of secondary particulate generation. The WSOC measurement method issued by Japan's Ministry of the Environment describes that it uses ultrapure water to extract WSOC from PM_2.5 collected on a filter, after which measurements are performed with a TOC analyzer or carbon analysis system. Diesel vehicles are one source of PM_2.5, and since the particles generated in diesel particulate matter are 1 μm or smaller, these particles are regarded as being an important part of PM_2.5 The main components of diesel particulate matter are carbon components, including WSOC. In this article, we will describe using the Shimadzu TOC-L total organic carbon analyzer to measure the WSOC content in diesel particulate matter based on the measurement method issued by Japan's Ministry of the Environment.

December 27, 2016 GMT