selwa ts

2021-11-17 12:04
(830 d 04:45 ago)

Posting: # 22673
Views: 1,946

 Use of NP (Normal Phase) columns in bioanalysis [Bioanalytics]

Hello dear community, I would like to know if we are called to use HPLC or UPLC MS columns in normal phase in bioanalysis?

Thanks in Advance
Vienna, Austria,
2021-11-17 12:43
(830 d 04:06 ago)

@ selwa ts
Posting: # 22674
Views: 1,579

 Hydrophilic Interaction Liquid Chromatography

Hi Selwa,

❝ I would like to know if we are called …

Nobody calls you to use anything. You can use any stationary phase (normal or reversed phase, diol, amino, ion-exchange, …) you like. As long as the method passes validation, all is good.*

❝ … to use HPLC or UPLC MS columns in normal phase in bioanalysis?

I would avoid normal phase if ever possible, since strongly non-polar mobile phases (e.g., hexane) in analytical grade are rather expensive and environmentally problematic.

I suggest HILIC instead, i.e., an RP column and a mobile phase consisting of a moderately non-polar (e.g., acetonitrile) component modified by adding <20% water. Pretty old approach.3,4
In my CRO we used it for amitriptyline/nortriptyline, clobutinol, and doxepin.
  • Pros
    • Much better suitable for (highly) polar compounds than RP.
    • Sometimes better for basic compounds than RP.
    • Mobile phase substantially cheaper than for normal phase LC.
    • Mobile phase more volatile than in RP nice for MS.
  • Cons
    • Mobile phase more expensive than for RP.
    • Method development might be more difficult; somewhat steeper learning curve.

  • Do you know GC-O1 or even GC/MS-olfactometry?2

  1. Acree TE, Barnard J, Cunningham G. A procedure for the sensory analysis of gas chromatographic effluents. Food Chem. 1984; 14(4): 273–86. doi:10.1016/0308-8146(84)90082-7.
  2. Song H, Liu J. GC-O-MS technique and its applications in food flavor analysis. Food Res Int. 2018; 114: 187–98. doi:10.1016/j.foodres.2018.07.037.
  3. Schmid RW, Wolf C. Use of unmodified silica with buffered aqueous mobile phase mixtures for selective chromatography of basic drugs. Chromatographia. 1987; 24: 713–9. doi:10.1007/BF02688574.
  4. Alpert AJ. Hydrophilic-interaction chromatography for the separation of peptides, nucleic acids and other polar compounds. J Chromatogr A. 1990; 499:177–96. doi:10.1016/s0021-9673(00)96972-3.

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selwa ts

2021-11-17 16:11
(830 d 00:38 ago)

@ Helmut
Posting: # 22675
Views: 1,464

 Hydrophilic Interaction Liquid Chromatography

Thank you for your quick and precise reactivity

Best Regards

Selwa ts
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