Application of urea adduction technique to polluted urban aerosols for the determination of hydrogen isotopic composition of n-alkanes

作者：Yamamoto Shinya^*; Kawamura Kimitaka

来源：International Journal of Environmental Analytical Chemistry, 2012, 92(3): 302-312.

DOI：10.1080/03067310903045505

• hydrogen isotope
• n-alkane
• urban aerosol
• urea adduction

We examined an applicability of an improved urea adduction technique for the determination of hydrogen isotopic composition (delta D) of homologous series of n-alkanes present in polluted urban aerosols using GC/TC/IRMS. Unresolved complex mixture (UCM) of hydrocarbons that interferes with accurate isotope measurements of n-alkanes was removed from n-alkane fraction by a urea adduction method. Recoveries of C-20 to C-30 n-alkanes during the urea adduction procedure were greater than 90% when the concentrations of total n-alkanes exceed 6.1 mu g mL(-1). Our compound-specific D/H ratios confirm the absence of significant hydrogen isotope fractionation in n-alkanes during urea adduction and recovery of the purified n-alkane fraction. We applied this technique to the urban aerosols that contain a large quantity of UCM to measure delta D of C-20 to C-35 n-alkanes in urban aerosols from Tokyo and Sapporo with an accuracy less than 10 parts per thousand. We found that the delta D values widely ranged from -38 to -179 parts per thousand. Based on the delta D values of individual n-alkanes in aerosol samples, we can obtain further information on the sources of aerosol n-alkanes and their source regions, and the atmospheric processes such as long-range transport and atmospheric mixing of air masses of different origin.

• 出版日期2012