glycols by LC/MS/MS

[twranger]

Hello,
Out here on the front lines of hydraulic fracturing water analysis, currently analyzing glycols by GC method 8015 direct injection, with the problems of water and high salts in these samples. Just heard that the USEPA is moving toward using a modification of Method 8321, direct injection of water samples into a LC/MS/MS to achieve much lower detection limits. This seems like an expensive, complicated way to go for compounds that biodegrade, but does anyone have experience using HPLC for ethylene glycol and related compounds?

[sepscientologist]

diols are a nuisance for me. No UV, no ELSD, decompose on the inlet by GC. I have had no choice but go to
a HILIC LS/MS/MS method for diols. Derivatizations can work such as BSTFA but if your sample matrix is water
the reagent is not soluble and there is just too much water. Not a lot of options.

[KM-USA]

We have used GC after solubilization in DMF and trimethylsilyl dervatization for glycols for for three decades, in samples up to 95% water. And GCMS for 23 years for those.

[twranger]

KM- can you provide more info? I have heard of phenylboronic derivitization used in clinical labs, but the limits are similar to direct injection, ours at 10ppm. These samples are 100% aqueous, with large levels of dissolved solids. Do you run the derivatized glycols on the GCMS, or is that a seperate method?

For those interested, here is the EPA page discussing these new analytical challenges:

[http://www2.epa.gov/sites/production/files/documents/acm-technical-workshop-webinar.pdf]

[KM-USA]

KM- can you provide more info?

http://www.ncbi.nlm.nih.gov/pubmed/20587351

Journal of the American Oil Chemists Society, Vol. 64, No. 9 (September 1987), pp. 1356-1357.

Yes, same procedure, same autosampler vials go to either GC or GCMS. Just need to ensure excess derivatizing agent.

[Petrus Hemstrom]

There is a paper on diethylene glycol by LC-MS some years ago.

Identification and Quantification of Diethylene Glycol in Pharmaceuticals Implicated in Poisoning Epidemics: An Historical Laboratory Perspective
D. B. Barr, J. R. Barr, G. Weerasekera, J. Wamsley, S. R. Kalb, A. Sjödin, J. G. Schier, E. D. Rentz, L. Lewis, C. Rubin, L. L. Needham, R. L. Jones, E. J. Sampson
J. Anal. Toxicol., 31 (2007) 295-303 [pdf]

If you dont have access to that we have a technical not on it on our web site
http://www.sequant.com/files/documents/ ... graphy.pdf

[rb6banjo]

The structure for DEG is not what is depicted in that paper. You might want to fix it if you can.

DEG:



The molecule depicted in the paper is called erythritol.

[Consumer Products Guy]

There is a paper on diethylene glycol by LC-MS some years ago.

Identification and Quantification of Diethylene Glycol in Pharmaceuticals Implicated in Poisoning Epidemics: An Historical Laboratory Perspective
D. B. Barr, J. R. Barr, G. Weerasekera, J. Wamsley, S. R. Kalb, A. Sjödin, J. G. Schier, E. D. Rentz, L. Lewis, C. Rubin, L. L. Needham, R. L. Jones, E. J. Sampson
J. Anal. Toxicol., 31 (2007) 295-303 [pdf]

If you dont have access to that we have a technical not on it on our web site
http://www.sequant.com/files/documents/ ... graphy.pdf

I'm just not sure why anyone would need or use LC-MS to determine diethylene glycol in pharmaceutical products. Its level would need to be significantly high in such pharmaceuticals, not at trace levels, so don't know why the specificity or detection limits of MS would be needed over GC-FID or HPLC.

[Consumer Products Guy]

The structure for DEG is not what is depicted in that paper. You might want to fix it if you can.

DEG:



The molecule depicted in the paper is called erythritol.

Agree, wrong structure in that Merck application. Also, the first sentence in the Conclusions section is incorrect, should state: "If ethylene glycol, a solvent used in anti-freeze is used in place of glycerin in a pharmaceutical preparation....."

See http://www.ncbi.nlm.nih.gov/pubmed/20587351 for a way to look for either ethylene glycol or diethylene glycol adulteration.