Contamination?
Chromatography Forum: LC Message Board: Contamination?
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By readski on Wednesday, July 28, 2004 - 09:01 am:

After installing a new 4L bottle of HPLC grade methanol on my Agilent 1100 system(with vacuum degasser), I have a new contamination peak in my gradient method. I am running a 72-100% methanol gradient with an acetate buffer on a C08 hypersil column. This peak only appears on this gradient (other gradients start at 87%). I have also found this on other systems with the same gradient (so it's not specific this system or column)

While not a GC expert, I ran a sample of this on GC and noticed a small peak (<1% by area of total methanol peak) that is not present in normal HPLC grade methanol. Based on retention time I would think this could be Acetone, but we sent it out to the "experts" and they found nothing wrong.

Since we are a large user of methanol we get cases of 4 liter bottles (4 in a case). My GC analysis has found this contamination in several bottles but not all of the same case (contaminated methanol lot number is always the same). Only those bottles that show the GC peak cause the HPLC problem.

Anybody have a clue to what I am experiencing?

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By DR on Thursday, July 29, 2004 - 06:31 am:

I'd guess you're experiencing a case of MeOH that, whill probably well within manufacturer's specifications, is not suitable for your analysis. Start cracking bottles with different lot marks and stash a few bottles of whatever works.

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By Chris on Wednesday, August 11, 2004 - 01:33 pm:

We put a lot of faith in suppliers of chemicals, I have used Methanol from Fisher scientific (one of the major suppliers in the UK) and an entire batch of HPLC methanol was contaminated with Hexane from the previous production.

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By HPLC Dave on Thursday, August 12, 2004 - 03:24 am:

Never had a problem in 15years with VWR (Merck) solvents for HPLC.
HPLC acetonitrile & 0.1%TFA in HPLC water.
Other suppliers have not been so good!
However, I don't use their HPLC Methanol for mobile phase - only dilutions.

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By HPLC Dave on Thursday, August 12, 2004 - 03:28 am:

I was not implying that I would not use VWR HPLC methanol as mobile phase. I just use their HPLC acetonitrile instead (less pressure in gradients etc).

Readski: I'm sure VWR methanol would be worth a try in your HPLC system.

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By readski on Monday, August 16, 2004 - 06:54 am:

To all: We are using JT Baker... and have have not seen this problem before. Thanks for your imputs.

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By loren on Tuesday, August 17, 2004 - 04:40 pm:

My name is Loren Lee, I am a North American Regional Director of Fulltime Chemical
corporation, We are a packaging products and chemical material industrial Acetonitrile , HPLC ACETONITRILE & HPLC-M ACETONITRILE manufacturer, we also a manufacturer of some others chemical materials used as HPLC solvents, like
ACETONE, CARBON TETRA CHLORIDE, CHLOROFORM, METHANOL, ISO PROPYL ALCOHOL, ETHYL ACETATE, DIMETHYL FORAMIDE, ETHYL METHYL KETONE, ISO OCTANE, N-HEPTANE, N-HEXANE, WATER, ETRAHYDROFURAN

We would like to provide better quality and price
for your firm.

Here is my company website:
http://www.fulltimeholdings.com/index2.htm

Thanks