Short name:
GC-FID

Full name:
Gas Chromatography - Flame Ionization Detector

What is being measured:
Hydrocarbon Concentrations

Sampling Protocol:
Online

Manufacturer:
Agilent

Model:
6890N

Instrument year :
2005

Data recording software:
Agilent ChemStation

Data analysis software:
Custom Excel Program

Raw data time resolution:
1s

Analysis data averaging:
10~20 min

Detection limit:
0.1 ppb

Sensitivity to temperature (and correction method, if applicable): :
N/A

Sensitivity to relative humidity (and correction method, if applicable): :
N/A

Sampling method:
Direct gas sampling

Sample preparation method:
Filter particle contents before sampling

Sample residence time (chamber to instrument) (seconds):

Length of tubing (cm):

Instrument flow rate:

Tubing inner diameter:
1/4'' OD; 0.152'' ID

Tubing material:
FEP Teflon

Chemical identification method:
Retention time of hydrocarbons in a known column is used to pre-calibration and different VOCs can be assigned to specific peaks.

Data analysis method:
The built-in ChemStation program converts the raw signal to formatted data in scan reports, then the data is extracted by a custom Excel script.

Quantification method:
Integration of ChemStation peaks multiplied by a response factor determined from calibration to output ppb data

Calibration method:
Performance calibration: sample known concentration of Hexane gas and compare the result to the pre-calibration data to make sure the instrument is in a good working state. THIS IS DONE BEFORE EACH EXPERIMENT STARTS. Hydrocarbon calibration: calibration with three or more dilutions of known hydrocarbon concentrations in FEP Teflon bags (pillow bags). THIS IS DONE ANNUALLY.

Calibration drift estimate:
Low (on the order of weeks)

Calibration schedule:
Annually

Uncertainty estimation method:
N/A

Known interferences:
Column backgrounds

Link to supplemental information:
N/A

Additional notes:
N/A

Measurement uncertainty:
(a) Local_Time (N/A); (b) Experimental_Time (N/A); (c) VOC_Concentration (+/- ?%); (d) Tracer_Concentration (+/- ?%)

Measurement units:
(a) Local_Time (N/A); (b) Experimental_Time (min); (c) VOC_Concentration (ppm); (d) Tracer_Concentration (ppm)