Column types for LC-MS/MS?

To MiK***: It depends. -> need to order the column according the analyte in your Lab.

Here is the column info I sued @ 2005' Tech.

2: eclipse c18 150 mm * 4.6 mm ,5 um.
1: zorbax-aq 150 mm * 4.6 mm, 3.5 um.
2: zorbax-aq 250 mm * 4.6 mm, 5 um.
4: zorbax-sq 50 mm * 4.6 mm, 5 um.
3: YMC-am-c18 50 mm * 4.6 mm, 5 um.
4: Waters C18 50 mm *2.0mm ， 5 um.

LC-MS: Prefer use the zorbax-sq 50 mm *4.6 mm,5 um and Waters C18 50 mm *2.0 mm，5 um, HUGE time saving with Syringe pump.

LC only: eclipse c18 150 mm *4.6 mm and zorbax-sq 50 mm *4.6 mm.

DONE! Annual Calibration of Agilent 6890N GC/FID

Update @ Wed.
using the Solution of 0.03% C14, C15 and C16 normal alkanes in hexane.

Then the calibration for Varia** 240 FS Atomic Absorption Spectrometer.
hope get it done NLT this Friday.

Thanks..

Polydimethylsiloxane (PDMS) Fibers ( non-polar) should be OK for the Flavor Components (2)

To Je***: Based on the searching on my NIST/EPA/NIH 2005 Mass Library, I got some crabs :>) Peak @ 21.36 min -> 2，6-di-tert-butyl-4-sec-butylphenol

Peak @ 30.91 min -> 4-sec-butyl-2-tert-butylphenol

So please DO NOT trust this Mass Library Searching. will update when I find something new.
Update@Aug-12-2008
Maybe PDMS works. Also it maybe work on the acids, alcohol, aldehydes (ketone). However, that is not a good one. -> “the Supelco 57301 the fiber ( 100 um) PDMS” has better SPE affinity to the high molecular weight non-polar compounds, that maybe the reason you got so many unknown peak ( high molecular compounds).
So if your analyte is low molecular polar acid, alcohol, aldehydes (ketone), recommend the SPME fiber assembly, Carbpwax-Polyethyele (PEG), Supelco#57355-U, it should be good to go for the polar low molecular compounds.

Polydimethylsiloxane (PDMS) Fibers ( non-polar) should be OK for the Flavor Components (1)

To: Je***: Polydimethylsiloxane (PDMS) ( non-polar) should be Good. What is the thickness of matrix active group (polydimethylsiloxane coating)? using 100μm coating? that 100 μm coating thickness is recommended for low molecular weight or non-polar high molecular weight compounds. Or equivalent with the one in the Your Reference Literature?

If want to obtain a decent result, need to pay attention to the optimization of the SPME method with PDMS: Carry-over effect / Position of the fiber in the GC injector/ Extraction conditions, such as the duration of absorption and desorption, temperature of extraction, and the polarity and structure of the fiber. (Here is the basic SPE info:
http://www.sigmaaldrich.com/Brands/Supelco_Home/Spotlights/SPME_central.html)
If use the 30 μm or a 7 μm PDMS fiber, could extract the non-polar semivolatiles or large molecular weight compounds more effectively.

So my suggestion is: try to do more research on that papers -> find out the right PDMS fiber they used. (100 μm coating or 30 μm or a 7 μm)?

Reference from Varia**: https://www.varianinc.com/media/sci/apps/spme04.pdf