Quantification of black carbon in marine systems using the benzene polycarboxylic acid method: a mechanistic and yield study

摘要: LIMNOLOGY and OCEANOGRAPHY: METHODS Limnol. Oceanogr.: Methods 9, 2011, 140–149 © by the American Society of Limnology Oceanography, Inc. Quantification black carbon in marine systems using benzene polycarboxylic acid method: a mechanistic yield study L. A. Ziolkowski 1,2 *, A.R. Chamberlin 3 , J. Greaves E.R.M. Druffel 1 Department Earth System Science, University California Irvine, CA 92697 Origins Institute, McMaster University, Hamilton, Ontario L8S 4L8 Chemistry, Abstract (BC), carbonaceous material pyrogenic origin, has typically required either chemical or thermal oxidation methods for isolation from heterogeneous matrices, such as sediment soil. The (BPCA) method involves aromatic structures, those BC, into BPCAs. We revised BPCA with intent to quantify BC dissolved organic (DOC). As part this work, we evaluated mechanism nine polycyclic hydrocarbons (PAHs) six reference materials. After 8 h at 180°C, average car- bon was 26 ± 7% C not correlated molecular weight PAH oxidized. majority observed BPCAs were nitrated, which serious implications quantification BC. Smaller PAHs favor formation less substituted BPCAs, whereas larger PAHs, coronene, more fully Time-course experiments revealed variations distributions over time, favoring longer times, exhibited little variation. No decarboxylation mellitic (B6CA) during time course experiments. Using model compound anthracene, potential internal standard, propose reaction based on time-course experiment data. materials that revision is significantly efficient than previous versions effective quanti- fying both char soot quantifying (Masiello 2004). Various techniques are used isolated environmental matrices including (Gustafsson et al. 1997), chemi- cal (nitric acid: Glaser 1998; Brodowski 2005; dichromate: Wolbach Anders 1989) mild photo-oxidation (NaClO, Simpson Hatcher 2004; ultra-violet radiation, Skjemstad 1996) followed NMR. (Glaser 2005) converts rings various numbers (2-6) carboxylic groups. Assuming within sample additional neither added nor exchanged, provides general struc- tural information about Nitric oxidizes structure single ring preserved acids derived adjacent side chains. This retains structure, essential subsequent isotopic abundance assays Black (BC) particles byproducts combustion processes can be defined broad range characteris- tics. Sizes nanometer millimeter pieces charcoal. Chemically, condensed, highly (Fig. 1). Environmental scientists inter- ested isolating soils sediments, address questions regarding scales storage system. wide ranges physi- characteristics it found pose challenges when *Corresponding author: E-mail: lorized@gmail.com Acknowledgments authors would like thank Sheila Griffin Claudia Green their help work. gift M.W.I. Schmidt D. M. Smith. manuscript benefitted com- ments Associate Editor Elizabeth Minor two anonymous reviewers. acknowledge funding NSF Chemical Oceanography Program. DOI 10:4319/lom.2011.9.140