by 
EFT » 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