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We evaluate theapplicability of an optical transmission measurement method commonly used forthe analysis of the Black Carbon BC content of aerosol sample, to determinethe BC content of loess sediments. A number of different sample pretreatmentprocedures are developed and compared, leading to an optimum preparationprocess. The results include: 1 Subtraction of the optical attenuation valuesbefore and after heating of the sample filters -ΔATN- varies linearly with the samplemass. The slope of the regression line provides the best determination of BCconcentration. 2 When the sample mass is small, NaPO36 pretreatment is best for BC measurement, and the BC concentration results aregiven by the slope of the regression between ΔATN and sample mass, for a series of samples of varying mass. 3 HFpretreatment accompanied by centrifugation and rinsing may produce a negativebias on the result. 4 Replicate measurements of BC for loess samples showed amaximum deviation less than 5.6%, suggesting that measurements of the BCconcentration of a sequence of loess samples could determine variations to thisdegree of significance. 5 The overall trends of BC concentration in loesssection sequences were similar for all chemical pretreatments. The BCconcentration result for replicate samples is comparable when pretreated by thesame procedure.

KEYWORDS

Black Carbon, Optical Measurement Method, Loess Section, Pretreatment Procedure

Cite this paper

Mu, Y. , Qin, X. , Liu, J. and Yin, Z. 2015 Methods Development for the Optical Determination of the Black Carbon Content of Loess Samples. American Journal of Analytical Chemistry, 6, 585-603. doi: 10.4236-ajac.2015.67057.





Autor: Yan Mu1*, Xiaoguang Qin1, Jiaqi Liu1, Zhiqiang Yin2

Fuente: http://www.scirp.org/



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