AutoGC

General
General discussions not specific to any other category.

Chromatography
General discussion of factors that affect chromatographic resolution, peak shape, and noise in the raw data.

Data Systems
All AutoGC systems collect, identify and quantitate the VOC targets using a data system. This category is dedicated to discussions of the methods used by data systems for this purpose. The data system may additionally control GC methods as well as thermal desorption methods, as well as relays used for the automation of introduction of routine quality control samples.

Thermal Desorption
Ambient air samples are generally concentrated using adsorption on absorbents capable of trapping C2 - C12 hydrocarbons and then thermally desorbed into the gas chromatograph. This forum is for the discussion of issues found in the equipment and process of thermal desorption such as its effects on recoveries, retention times, and overall chromatographic effects caused by poor or incorrectly functioning thermal desorbers.

Quality Control
This forum is dedicated to the discussion of issues related to quality control such as standards, calibrations, target recoveries and audits. Issues on the automation of regular quality control samples as well as identification and the evaluation of quality control checks may also be included here. The routine validation of the AutoGC data may also be addressed.

Data Validation
Validation of AutoGC data is the last step in preparation for submission to the EPA Air Quality System (AQS). There are several levels of validation from simple review of chromatography and quality controls to verify that the instrumentation is functioning within specification to more advanced comparisons with historical data and typical ambient air profiles.