The new instrument using a TC–BC (total carbon–black carbon) method for the online measurement of carbonaceous aerosols

• Main Authors: M. Rigler, L. Drinovec, G. Lavrič, A. Vlachou, A. S. H. Prévôt, J. L. Jaffrezo, I. Stavroulas, J. Sciare, J. Burger, I. Kranjc, J. Turšič, A. D. A. Hansen, G. Močnik
• Format: Article
• Language: English
• Published: Copernicus Publications 2020-08-01
• Series: Atmospheric Measurement Techniques
• Online Access: https://amt.copernicus.org/articles/13/4333/2020/amt-13-4333-2020.pdf

<p>We present a newly developed total carbon analyzer (TCA08) and a method for online speciation of carbonaceous aerosol with a high time resolution. The total carbon content is determined by flash heating of a sample collected on a quartz-fiber filter with a time base between 20&thinsp;min and 24&thinsp;h. The limit of detection is approximately 0.3&thinsp;<span class="inline-formula">µ</span>g&thinsp;C, which corresponds to a concentration of 0.3&thinsp;<span class="inline-formula">µ</span>g&thinsp;C&thinsp;m<span class="inline-formula">⁻³</span> at a sample flow rate of 16.7&thinsp;L&thinsp;min<span class="inline-formula">⁻¹</span> and a 1&thinsp;h sampling time base. The concentration of particulate equivalent organic carbon (OC) is determined by subtracting black carbon concentration, concurrently measured optically by an Aethalometer^®, from the total carbon concentration measured by the TCA08. The combination of the TCA08 and Aethalometer (AE33) is an easy-to-deploy and low-maintenance continuous measurement technique for the high-time-resolution determination of equivalent organic and elemental carbon (EC) in different particulate matter size fractions, which avoids pyrolytic correction and the need for high-purity compressed gases. The performance of this online method relative to the standardized off-line thermo-optical OC–EC method and respective instruments was evaluated during a winter field campaign at an urban background location in Ljubljana, Slovenia. The organic-matter-to-organic-carbon ratio obtained from the comparison with an aerosol chemical speciation monitor (ACSM) was <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow><mrow class="chem"><mi mathvariant="normal">OM</mi><mo>/</mo><mi mathvariant="normal">OC</mi></mrow><mo>=</mo><mn mathvariant="normal">1.8</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="70pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="47eef3744f0d0ab176dfa9f9d97c5439"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-13-4333-2020-ie00001.svg" width="70pt" height="14pt" src="amt-13-4333-2020-ie00001.png"/></svg:svg></span></span>, in the expected range.</p>