Follow NEMC
 |
 |
 |
Analysis of Particulate and Vapor Phase Semi-Volatile Organic Compounds in Indoor Air Using Thermal Desorption Gas Chromatography-Mass Spectrometry
Oral Presentation
Prepared by H. Hayes, D. Benton, J. Arnold
Eurofins Air Toxics, Inc., 180 Blue Ravine Rd. Suite B, Folsom, CA, 95630
Contact Information: hhayes@airtoxics.com; 916-985-1000
ABSTRACT
Identifying and measuring semi-volatile organic compounds (SVOCs) are of increasing interest in assessing indoor air quality and quantifying human health risks. Sources of SVOCs in indoor air include household activities such as cooking, use of fireplaces, and smoking as well as emissions from building materials and household products, and intrusion of outdoor air. The conventional methods for measuring SVOCs in indoor air use a combination of filters to collect the particulate-associated fraction and sorbents such as XAD resin to capture gas-phase contaminants. Both the filter and sorbent cartridge are extracted together as one sample using an organic solvent. While effective, these methods require a large volume of air to provide the desired sensitivity, and the solvent extraction step requires significant labor and resources in the laboratory. As an alternative to solvent extraction, thermal desorption techniques allow for the direct analysis of the collection media, thereby eliminating the off-line preparation steps and providing improved sensitivity since a large portion of the sample is transferred to the analytical unit. Despite the advantages of thermal desorption, the low vapor pressure of SVOC compounds present a challenge in selecting the appropriate collection media and desorption parameters. The media must retain the most volatile compounds at the desired sampling volume while efficiently releasing the least volatile particulate-associated compounds during the thermal desorption step. Desorption parameters must be optimized to insure complete transfer of the target compounds from the media through the secondary trap and transfer line to the GC.
A method using thermal desorption coupled with GC-MS was developed to measure indoor air SVOCs in the vapor and particulate phase. The SVOCs evaluated by this method include a list of PAHs ranging from naphthalene to 5- and 6-ringed PAHs, such as benzo(a)pyrene and benzo(ghi)perylene. Several combinations of filters and sorbents are evaluated for recovery and ease of use, and analytical performance data including sensitivity, linearity, and precision are presented. Performance of the thermal desorption method is compared to the conventional solvent extraction technique by collecting concurrent indoor air samples. Advantages and limitations of the thermal desorption method are presented.
Oral Presentation
Prepared by H. Hayes, D. Benton, J. Arnold
Eurofins Air Toxics, Inc., 180 Blue Ravine Rd. Suite B, Folsom, CA, 95630
Contact Information: hhayes@airtoxics.com; 916-985-1000
ABSTRACT
Identifying and measuring semi-volatile organic compounds (SVOCs) are of increasing interest in assessing indoor air quality and quantifying human health risks. Sources of SVOCs in indoor air include household activities such as cooking, use of fireplaces, and smoking as well as emissions from building materials and household products, and intrusion of outdoor air. The conventional methods for measuring SVOCs in indoor air use a combination of filters to collect the particulate-associated fraction and sorbents such as XAD resin to capture gas-phase contaminants. Both the filter and sorbent cartridge are extracted together as one sample using an organic solvent. While effective, these methods require a large volume of air to provide the desired sensitivity, and the solvent extraction step requires significant labor and resources in the laboratory. As an alternative to solvent extraction, thermal desorption techniques allow for the direct analysis of the collection media, thereby eliminating the off-line preparation steps and providing improved sensitivity since a large portion of the sample is transferred to the analytical unit. Despite the advantages of thermal desorption, the low vapor pressure of SVOC compounds present a challenge in selecting the appropriate collection media and desorption parameters. The media must retain the most volatile compounds at the desired sampling volume while efficiently releasing the least volatile particulate-associated compounds during the thermal desorption step. Desorption parameters must be optimized to insure complete transfer of the target compounds from the media through the secondary trap and transfer line to the GC.
A method using thermal desorption coupled with GC-MS was developed to measure indoor air SVOCs in the vapor and particulate phase. The SVOCs evaluated by this method include a list of PAHs ranging from naphthalene to 5- and 6-ringed PAHs, such as benzo(a)pyrene and benzo(ghi)perylene. Several combinations of filters and sorbents are evaluated for recovery and ease of use, and analytical performance data including sensitivity, linearity, and precision are presented. Performance of the thermal desorption method is compared to the conventional solvent extraction technique by collecting concurrent indoor air samples. Advantages and limitations of the thermal desorption method are presented.