Does anyone have a GC/MS method for analyzing AA in hops? - Home Brew Forums
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Old 07-04-2008, 01:43 PM   #1
KingBrianI
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I'm not sure if this is the right section to post this but it looked as good as any so here goes. I'm wondering if anyone has a GC/MS method for analyzing the alpha acids in hops. I guess I could run a google search but I thought it would be easier and more fun if someone here knew. I analyze agricultural and environmental samples for pesticides every day at work and switching to AA would be a snap. I want to grow my own hops and figure they would be much more useful if I had a hard AA% for them. Anyway thanks for any information!



 
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Old 07-04-2008, 02:42 PM   #2
seanhagerty
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bro, if you get that method, I want the info on it. I'd be interested in know mine too

Sean


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Old 07-04-2008, 10:48 PM   #3
King of Cascade
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If you could accurately calculate the AA of home grown hops you would be the most popular person on this site.

 
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Old 07-04-2008, 11:30 PM   #4
Special Hops
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Kanatenah
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What is a GC/MS method?

 
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Old 07-04-2008, 11:42 PM   #5
seanhagerty
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a gc/ms method is a program (for lack of a better term) that tells a GC/MS how to operate.

Sounds easy, but the trouble is, you have to have access to a GC/MS, which are not cheap to own or operate.

http://www.gmu.edu/departments/SRIF/...gcd/gc-ms2.htm

This is a link that gives a down and dirty on what they are.


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Old 07-05-2008, 12:20 AM   #6
KingBrianI
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Yeah, lucky for me we have lots of GCs and HPLCs at work. I think the AAs would best be characterized on the GC. Problem is I would need to create a standard curve. I could either source raw AA from somewhere or extract hops of known AA content and use them to construct the calibration curve. Either way an expensive proposition. It's looking like I may have to do some research and either find a published method or attempt to create my own method. Hopefully someone who can help is on vacation today and can provide me with information when they get back and see this.

 
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Old 07-07-2008, 01:08 AM   #7
PseudoChef
 
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I have a protocol for measuring using UV-Vis (I think) if you are interested. I'll have to dig it out of our club archives for you.

If you have a GC/MS and HPLC, I'm sure you have access to a Uv-vis.

 
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Old 07-07-2008, 01:20 AM   #8
clayof2day
 
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Hey Kyle,

I'd be interested in the UV/Vis protocol you have. If you want to email it to me, just shoot me a PM and I'll get you my email. Unless its in my profile, I don't know.

Matt
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Old 07-07-2008, 12:32 PM   #9
KingBrianI
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pseudochef, please post up the method if you find it. i looked around the internet for a bit and found a lc/ms/ms method i can use but i'd like to see other methods as well.

 
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Old 07-07-2008, 01:15 PM   #10
Piotr
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here:
http://www.beertools.com/forum/viewtopic.php?t=5135
is an interesting discussion about calculating AA in Homegrown hops. Too complicated for me I'm afraid...



 
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