Chromatography Forum

Hello all,

As a clinical pathologist, I would like to introduce LC-MS/MS for Vitamin D, testosterone, cortisol and a few other like 17-OH-progesterone. However, I am familiar with immuno-assays only and chromatographic techniques frighten me.

Do you think it is time to introduced those techniques in the "routine" clinical laboratory? Can those tests be performed fast enough and are they "rugged" enough?

Kind regards,

Speaking as a chromatographer, immunoassays frighten me!

While I'm not a clinical chemist, my impression has always been that the advantage of LC is much lower development cost and that if an immunoassay kit for a particular analysis exists, it will usually be faster/cheaper than LC or LC-MS.

I can second Tom´s fear about immunoassays, but because of thousands which we ran in the lab of the neurosurgery in Giessen. Especially small molecules, present in any mammal, are connected with difficulties, thus the publication on the comparison of HPLC with RIA, ELISA: J Chromatogr B, 678, 137 (1996). If a guess at the values is sufficient than immunoassays will do (the values for some patients can be WAY off, but in an aura where extending the time of death of a certain percentage of patients for a few weeks is considered a great advance it´s not tht bad).
If you do get into LC-MS/MS .... somone will have to know what they are doing, and if you have a good person in place, the medical staff might have to get used to qualifying statements rather than just numbers.

Dear Colleague,

you are right to choose LC MS instead of immunoassays: better specificity and sometimes the opportunity to have intersting by-products like 24 hydroxylated vitamin D, D2 vitaminforms, cortisol/cortisone ratio for 11 bHSD evaluation and so on...I am very fond of multi-analyte HPLC .

Be aware you'll need competent people, budget and...time.

Groetjes!

HPLC methods that are useful for the clinical lab have been around for quite a while. I was involved in the development of methods and the publication of such methods as long ago as 1984.

Recently LC/MS methods have been developed and are now in routine use for neonatal screening. If you are interested, check at the website of Waters, or contact a Waters rep for information.

Considering the nature of your compounds as well as your matrices, I recommend to talk to experts or look into the literature about the standard sensitivity limits for your analytes. If they are OK, then LC/MS is not a problem. Otherwise, you will need to consider sample prep methods.