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Topic: Difficulties with Perfluorinated Compounds (PFC) extraction in Butter  (Read 4757 times)

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Offline a confused chiral girl

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Hi Everyone  :)

I'm wondering if anyone is familiar with the extraction of PFC compounds (such as PFOA, PFOS etc) in butter using the HPLC-MS/MS. As butter has so much fat and barely any liquid, it's so hard to extract the compounds...as I've tried using acetone:hexane, ACN, DCM... using liquid-liquid then SPE.

Does anyone have any other plausible solutions? :)

Thank you!

Offline Golden_4_Life

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Re: Difficulties with Perfluorinated Compounds (PFC) extraction in Butter
« Reply #1 on: February 11, 2010, 02:54:20 PM »
1. extract 1 g margarine with 50 mL chloroform
2. centrifuge for 5 mins @ 6000 rpm
3. recover supernate and filter thru a #5 Whatman
4. recover filtrate and evaporate under N2 flow
5. reconstitute in acetone:chloroform 1:1 and measure UV-Vis; set to scan from 190nm to 500 nm to qualify the extract against a PFC Std.
Golden4Life

Offline a confused chiral girl

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Re: Difficulties with Perfluorinated Compounds (PFC) extraction in Butter
« Reply #2 on: February 11, 2010, 06:05:35 PM »
1. extract 1 g margarine with 50 mL chloroform
2. centrifuge for 5 mins @ 6000 rpm
3. recover supernate and filter thru a #5 Whatman
4. recover filtrate and evaporate under N2 flow
5. reconstitute in acetone:chloroform 1:1 and measure UV-Vis; set to scan from 190nm to 500 nm to qualify the extract against a PFC Std.

the instrument available for analyzing the results is the LC-MS/MS, so measuring the UV-Vis wouldn't be an option...as we don't base on the UV radiation. can this method still be used if it's on the hplc or uplc-MS/MS?

thank u  :P

Offline MOTOBALL

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Re: Difficulties with Perfluorinated Compounds (PFC) extraction in Butter
« Reply #3 on: February 14, 2010, 11:26:09 AM »
Follow the directions from Golden 4 Life to step 4.

At step 5, reconstitute in an appropriate LC-MS/MS diluent, e.g. aq. 2 mM Amm. acetate/MeOH (~60:40, based on the initial gradient condition below).

Details are lifted from a Thermo Scientific application note.

LC/ESI/MS
LC System: Thermo Scientific Rheos 2000 pump
Column: Hypersil GOLD 3 μm, 50 × 2.1 mm
Part Number: 25003-052130
Mobile Phase: A: 2mM NH4Ac in water/methanol (95:5)
B: 2mM NH4Ac in methanol
Gradient: Time (min) .. %B
0.0 .... 55
3.0 .... 85
3.1 .... 95
4.0 .... 55
5.0 .... 55

Flow Rate: 0.3 mL/min
Injection Volume: 10 μL
MS System: Thermo Scientific MSQ Plus™
Detection: Negative ESI (400° C, 90 eV)
Scan Range: 0–2.45 min SIM m/z 368.9; 2.46–4.0 min SIM m/z 498.8
Selected Ions: m/z 368.9 (fragment of PFOA m/z 412.8 → 368.9) m/z 498.8 (PFOS)
Dwell Time: 0.6 s

Mo

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