Quantitation of nitro- and dinitropol ycyclic aromatic hydrocarbons in diesel exhaust particulate matter.
Chemosphere 1986; 15(4):437-447
A chromatographic method for determining nitro and dinitropolycyclic aromatic hydrocarbons (nitroPAHs) in diesel exhaust particulates was described. Ten milligram (mg) samples were Soxhlet extracted with dichloromethane in the dark for at least 16 hours. The extract was concentrated just to dryness in a rotary evaporator, and prefractionated first on a silica Sep/pak cartridge and then on a high performance liquid chromatograph (HPLC) with a silica column. The HPLC column was eluted by a 99 to 1 hexane/dichloromethane mixture. The nitroPAH fraction was isolated and injected onto a capillary gas chromatograph fitted with an electron capture detector. When the method was tested using a standard reference sample, detection limits of below 10 micrograms per gram for most of the nitroPAHs, and recoveries of 47 to 120 percent, were achieved. Recoveries of 69 to 85 percent were attained for dinitropyrenes. The method was used to analyze diesel particulates from a heavy duty mining engine. The chemical composition of the diesel particulates was highly sensitive to operating conditions. Under 100 percent load, less than 3 percent of the soot collected consisted of soluble organic materials. Under reduced load and higher speed, the soluble organic fraction comprised 29 percent of the sample and contained higher concentrations of 1-nitropyrene (5522430) and other nitroPAHs. The author concludes that the method has a number of advantages, including requiring only 10mg of particulates and the ability to attain precise and accurate measurements of mono and di nitroPAHs.
NIOSH-Publication; NIOSH-Grant; Analytical-methods; Gas-chromatography; Organo-nitrogen-compounds; Chromatographic-analysis; Nitro-compounds; Analytical-instruments; Mutagens; Diesel-exhausts
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