Advertisement

Very small peaks

Discussions about GC and other "gas phase" separation techniques.

4 posts Page 1 of 1
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
Try inlet temperature around 280 C
Rt-2560 max. temp. is 250°C
Inlet and FID temp. 250°C should be O.K.

BTW - what is "FOG within sanitary system" ?
Rt-2560 max. temp. is 250°C
Inlet and FID temp. 250°C should be O.K.

BTW - what is "FOG within sanitary system" ?
Fats, Oils, and Greases
4 posts Page 1 of 1

Who is online

In total there are 25 users online :: 2 registered, 0 hidden and 23 guests (based on users active over the past 5 minutes)
Most users ever online was 4374 on Fri Oct 03, 2025 12:41 am

Users browsing this forum: Ahrefs [Bot], Google [Bot] and 23 guests

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry