Thursday, February 15, 2007

SPME of my beer

Finally, I am getting around to posting about the SPME (solid-phase microextraction) I did of one of my beers. SPME is pretty sweet. It involves dipping a fiber coated with what is usually on the inside of a GC column. Clever Canadian. The fiber is then placed in the GC/MS inlet port at about 300°C for 3 minutes. Any analytes are desorbed and sent to the MS detector via the 30m GC column (I can't remember what type of column I used).

In this case I used a fiber coated with 75μm of a carboxen/polydimethylsiloxane. The beer I chose was my second attempt at cloning Fat Tire Belgian Ale. A 4 mL sample was acidified to pH=2 and the fiber was placed in the sample while stirring for 15 minutes. The GC/MS trace is shown below:



I'd love to tell you what all of the peaks are, but you are going to have to wait until tomorrow. I have the list, but I'm tired and am going to bed.....

2 comments:

Matt Jenks said...

Any true analytical chemist worth his hops would get an authentic sample of Fat Tire to shoot through the machine. AND, if I remember correctly, you'll be getting Fat Tire soon enough to sample.

Lucky duck...

Vivek Gupta said...

The detection of chemical and biological warf are agents,encapsulated in monomolecular layers of functionalized alkanethiols radiological agents, and other hazardous vapors has significant deposited on interrogated microelectronics reversibly absorb vapors, import for both the military and homeland security efforts. Small, Monolayer swelling or dielectric alteration in the thin film caused lightweight, port able, and high sensitive sensors based on by absorption of the vapor molecules causes a small current. The nanomaterials are currently being developed and evaluated, system appears to have minimal water sensitivity, but can detect harmful vapors down to the parts per billion level or lower. http://www.nanoshel.com/product/barium-carbonate-medicine-powder/