Sorbent Media-Charcoal

Definition Definition  In line collection point for desired contaminant Purpose Purpose  Collection of particulate matter  Serves as “capture” point of sampling train for later analysis

Sorbent Media-Charcoal Specific Surface Area Specific Surface Area  >1000 m2/g Upper Temperature Range Upper Temperature Range  N/A Composition Composition  Coconut shell or petroleum-based charcoal

Sorbent Media-Charcoal Most widely used sorbent Most widely used sorbent OSHA/NIOSH methods based on charcoal OSHA/NIOSH methods based on charcoal Variety of sources Variety of sources  Coconut shells, coal, wood, peat, petroleum  Coconut shell and petroleum are most common

Sorbent Media-Charcoal High adsorptive capacity High adsorptive capacity  Micropourous structure  High surface area-to-weight ratio Ideal for sampling wide range of concentrations due to adsorptive capacity Ideal for sampling wide range of concentrations due to adsorptive capacity  High humidity can adversely effect  Use larger quantity of sorbent to overcome

Sorbent Media-Charcoal Limitations Limitations  Inefficient for very volatile low molecular weight HCs  Inefficient for low BP compounds  Unsuitable for reactive collection

Sorbent Media-Charcoal Method of Operation Method of Operation  Sample is collected or “absorbed”  Solvent is desorbed with appropriate solvent  Solute is then analyzed to determine elements and concentrations present

Sorbent Media-Charcoal Calibration Calibration  Rotameter  Flow is calibrated against ball “floating” in air in the chamber  Bubble tube(Manual or Electronic)  Flow is calibrated by timing bubble travel speed in vertical column

Sorbent Media-Charcoal Filter Cassettes Filter Cassettes Filter Cassette Holder Filter Cassette Holder

References Cited SKC Inc. Corporate Web Page accessed 04/03/01

Bibliography DiNardi Salvatore R. (1998) The Occupational Environment-Its Evaluation and Control, AIHA, Fairfax, Virginia DiNardi Salvatore R. (1998) The Occupational Environment-Its Evaluation and Control, AIHA, Fairfax, Virginia Goetsch David L. (1999) Occupational Safety and Health for Technologists, Engineers, and Managers, Prentice Hall, Upper Saddle River, New Jersey Goetsch David L. (1999) Occupational Safety and Health for Technologists, Engineers, and Managers, Prentice Hall, Upper Saddle River, New Jersey