Method for Determination of Carbon Content in Inhalable Particulate Matter in Air

Abstract

The invention relates to a method for measuring carbon content in inhalable particles in air, characterized in that a grading sampler using a quartz fiber filter membrane as a filter membrane and an infrared carbon flow instrument are used in the method. The method comprises the following steps: sampling for at least 12 h by using the grading sampler; taking out the quartz fiber filter membrane, and dividing the quartz fiber filter membrane into two parts; taking one part of the quartz fiber filter membrane and cutting up; putting the cut quartz fiber filter membrane in a high-temperature burned crucible to weigh, adding high-purity iron powder, using the infrared carbon flow instrument to obtain a measurement result which is the total carbon content (TC) (percentage content) in temperature rising process; taking another part of the quartz fiber filter membrane, heating up the part of the quartz fiber filter membrane in a muffle furnace to 405-445 DEG C, and keeping for 5-60 min; analyzing the carbon content in the infrared carbon flow instrument to obtain a measurement result which is the elemental carbon content (EC) (percentage content) ; and calculating the organic carbon content (OC) in a sample by using a subtraction method. The measurement result obtained by the method has reliable precision and accuracy.

Description

technical field [0001] The invention relates to environmental detection, in particular to a method for measuring inhalable particles in the air. Background technique [0002] For the monitoring of atmospheric particulate matter in the field of environmental protection, the current evaluation indicators in my country mainly focus on the evaluation of the mass concentration of particulate matter. But in the urban environment, the usually monitored air quality index (most of which are good) is not suitable for people's actual feeling, so for particulate matter, this makes people pay attention to the gradual improvement of the country's environmental protection requirements. The determination of organic carbon / elemental carbon is gaining more and more attention. Inhalable particulate matter in the atmosphere (PM10, refers to suspended particulate matter with an aerodynamic equivalent diameter of ≤10 μm) has a significant impact on atmospheric visibility, radiation intensity, re...

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Problems solved by technology

[0004] In the reported literature on the determination of carbon in inhalable substances by pyrolysis, the temperature of thermal analysis and separation of organic carbon is generally around 300°C. Under this condition, the decomposition of aromatic compounds is not complete, which affects the accuracy and precision of the test.

The main disadvantage of the optical method is that salt compounds such as iron salts absorb visible light, which can bring large random errors. At the same time, the optical method is not suitable for testing samples with high carbon content.

The photothermal method mainly includes thermo-optic transmission (TOT) and thermo-optic reflectance (TOR). The photothermal method can be applied to the test of samples with high carbon content, but like the conventional optical method, it cannot completely eliminate the salt. The Effect of Classes on Visible Light Absorption

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