S.O.P. No. MLD 031 - Determination of PM10 Total Carbon in the Ambient Air


This document describes a procedure for determining the total carbon content of particulate matter in the ambient air by the analysis of PM10 quartz-fiber filters.  This procedure was developed by MLD staff.


Atmospheric suspended particulate matter is collected over a 24-hour period on an (8x10 inch) quartz-fiber filter.  The filter is aspirated with a size selective inlet high volume sampler.  A #2 cork borer is used to punch circular pieces from the exposed filter.  Four filter punches are placed into the platinum sampling boat through a flip-top hatch on the Dohrmann carbon analyzer.  The sample boat is subsequently advanced through a pyrolysis tube which contains a packed section of Cobalt Oxide (CoO).  The pyrolysis tube is maintained at 800 C and is continually flushed with ultrapure oxygen at 200 cc/min. throughout the analysis.  The sample is vaporized and swept into the packed section of the pyrolysis tube where the carbonaceous matter on the filter is oxidized to CO2, H2O, SOx, NOx, etc.  The oxidized gases are then scrubbed to remove corrosive species formed and the resulting CO2 is carried into a linearized Non-Dispersive Infrared (NDIR) detector.  The Electronics Module integrates the detector signal and displays the analysis result in parts per million carbon (ppmC) concentration units.