TheĀ Fire Debris DatabaseĀ contains chromatographic data and information from fire debris samples that are truly representative of samples that would be encountered in casework. In addition, the ground truth (presence or absence of ignitable liquid residue) is known for each sample. Records consist of examples containing exclusively burned substrate materials as well as mixtures of burned substrates and ignitable liquid residues. Samples in the Fire Debris database are composed of ignitable liquid and substrate contributions that are represented in the ILRC and Substrate databases. NCFS prepares and analyzes samples in accordance with standard forensic test methods.
How to import the data file into Chemstation
Sample Preparation
Fire debris not containing an ignitable liquid are single substrates or a mixture of substrates (1 – 3).Ā These substrates originate from the substrates populating the Substrate Database.
Fire debris containing an ignitable liquid are a mixture of the fire debris not containing an ignitable liquid and a weathered ignitable liquid.Ā The weathered ignitable liquids originate from the ignitable liquids populating the ILRC database.
Instrument Parameters
Instrument and Accessories
Agilent 7890B gas chromatograph and 5977E mass spectrometer
Agilent ALS autosampler G2614A
GC Conditions
Column: HP-1 or equivalent
Length: 25 meters
Inner diameter: 0.20 millimeters
Film thickness: 0.5 microns
Carrier gas: helium (ultra high purity)
Flow: constant
Flow rate: 0.8 ml/min
Linear velocity: approximately 36 cm/sec
Split ratio: 50:1
Injection volume: 1 microliter
Pre-injection washes of sample: 2
Pumps: 2
Post-injection wash of solvent A: 10
Post-injection wash of solvent B: 10
Plunger speed: fast
Injection temperature: 250 degrees Celsius
Initial oven temperature: 50 degrees Celsius
Initial hold time: 3 min
Rate: 10 degrees Celsius per minute
Final temperature: 280 degrees Celsius
Final hold time: 4 min
Total run time: 30 min
MS Conditions
Transfer line temperature: 280 degrees Celsius
Acquisition mode: scan
Scan range: 30-350
Scan rate: 2-3 scans/sec; equivalent to 6-10 scans per peak
There is no solvent delay instead the detector is off between 1.54 and 2.00 minutes.