Very small peaks
Posted: Tue Mar 10, 2020 2:13 am
Hey All! I am in need of some assistance with very large solvent peaks and target peaks <50 mV. I'm new to working with GC's, other than what's taught in University courses. I currently have an internship with a local sanitary district, analyzing FOG within the sanitary system. Here's a quick rundown on my procedure. I first extract fatty acids within collected samples via Soxhlet extraction. Extract (4-6mg) is then mixed with 30mL of the trans-esterification solution (10:1:1 Chloroform, Methanol, Conc. HCl) and heated. 20mL of extraction solution (4:1 Hexane, Chloroform) and 1 mL DI water added and organic layer removed for analysis. I have set the attenuation to the highest sensitivity.
Here is my method of GC analysis:
Column: Rt-2560, 100 m, 0.25 mm ID, 0.20 µm
Inj. Vol.: 1 µL split (split ratio 20:1)
Liner: Premium 4 mm Precision liner w/wool (cat.# 23305.1)
Inj. Temp.: 225 °C
Oven Temp.: 100 °C (hold 4 min) to 240 °C at 3 °C/min (hold 15 min)
Carrier Gas He, constant flow
Flow Rate: 1.0 mL/min
Detector FID @ 285 °C
Make-up Gas Flow Rate: 45 mL/min
Make-up Gas Type: N2
Hydrogen flow: 30 mL/min
Air flow: 300 mL/min
https://imgur.com/JHNxd9Y
https://imgur.com/Uy39Ros
https://imgur.com/sYhphG3
Here is my method of GC analysis:
Column: Rt-2560, 100 m, 0.25 mm ID, 0.20 µm
Inj. Vol.: 1 µL split (split ratio 20:1)
Liner: Premium 4 mm Precision liner w/wool (cat.# 23305.1)
Inj. Temp.: 225 °C
Oven Temp.: 100 °C (hold 4 min) to 240 °C at 3 °C/min (hold 15 min)
Carrier Gas He, constant flow
Flow Rate: 1.0 mL/min
Detector FID @ 285 °C
Make-up Gas Flow Rate: 45 mL/min
Make-up Gas Type: N2
Hydrogen flow: 30 mL/min
Air flow: 300 mL/min
https://imgur.com/JHNxd9Y
https://imgur.com/Uy39Ros
https://imgur.com/sYhphG3