Applications:
Amino Acids Analysis in Acid Gradient Condition

11 underivatized amino acids (aspartic acid, glutamic acid, alanine, valine, methionine, isoleucine, cysteine, phenylalanine, histidine, lysine, and arginine) are separated by a Primesep 100 HPLC column by reversed-phase and ion-exchange mechanisms with LC/MS compatible conditions without the use of ion-pair reagents. The HPLC separation uses a TFA (trifluoroacetic acid) gradient in a mobile phase of water acetonitrile (MeCN, ACN with evaporative light scattering detection (ELSD).
Condition
Column |
Primesep 100, 4.6x250 mm, 5 µm, 100A |
Mobile Phase |
MeCN/H2O - 30/70% |
Buffer |
TFA , gradient 0.05-0.3 % , 25 min |
Flow Rate |
1.0 ml/min |
Detection |
ELSD |
Description
Class of Compounds
|
Drug, Acid, Hydrophilic, Ionizable, Vitamin, Supplements |
Analyzing Compounds |
Gaspartic acid, Glutamic acid, Alanine, Valine, Methionine, Isoleucine, Cysteine, Phenylalanine, Histidine, Lysine, Arginine |
AlanineAmino AcidsArginineAspartic AcidCysteineGlutamic AcidHistidineIsoleucineLysineMethioninePhenylalanineValine
Bufferless Ion Separation (BLIS™) Chromatography of Amino Acids (2)
Adding on to the previous HPLC separation of amino acids using Bufferless Ion Separation (BLIS) Chromatography; here we have additional amino acids separated on Primesep 200 column using only water and acetonitrile (MeCN, ACN) in the mobile phase. Primesep 200 is a reverse-phase (RP) column with weak acidic ion-pairing groups embedded. With no buffer present in the mobile phase, detection can be achieved with UV, mass spectrometry (MS), evaporative light scattering detection (ELSD).
Condition
Column |
Primesep 200, 4.6x150 mm, 5 µm, 100A |
Mobile Phase |
MeCN |
Buffer |
No |
Flow Rate |
1.0 ml/min |
Detection |
UV, 195 nm |
Description
Class of Compounds
|
Drug, Acid, Hydrophilic, Ionizable, Vitamin, Supplements, Amino acid |
Analyzing Compounds |
Aspartic acid, Alanine, Valine, Methionine, Leucine |
AlanineAmino AcidsAspartic AcidLeucineMethionineValine
HPLC Separation of Lysine and Arginine from Other Amino Acids
Application Notes: Amino acids are polar ionic compounds which are not retained on reversed-phase column without ion-pairing reagent. In our application, lysine and arginine can be separated from other amino acids. Amino acids with a pH between 3 and 5 and with one basic and one acidic group become very polar. Therefore these amino acids don’t have strong ion-exchange interaction with Primesep C stationary phase. Amino acids with two amino groups still carry positive net charge and can interact with stationary phase by cations-exchange mechanism. pH variation of the mobile phase can be an effective tool to adjust selectivity of separation for zwitter-ionic, basic and acidic compounds. This method can be used for separation of mono-charged compounds from compounds having an extra charge.
Application Columns: Primesep C
Application compounds: Aspartic acid, Glutamic acid, Aspargine, Glycine, Proline, Alanine, Phenylalanine, Tyrosine, Leucine, Lysine, Arginine
Detection technique: UV, LC/MS, ELSD/CAD
Condition
Column |
Primesep C, 4.6x150 mm, 5 µm, 100A |
Mobile Phase |
MeCN - 15% |
Buffer |
AmAc pH 5.0- 15 mM |
Flow Rate |
1.0 ml/min |
Detection |
ELSD |
Description
Class of Compounds
|
Drug, Acid, Hydrophilic, Ionizable, Vitamin, Supplements |
Analyzing Compounds |
Aspartic acid, Glutamic acid, Aspargine, Glycine, Proline, Alanine, Phenylalanine, Tyrosine, Leucine, Lysine, Arginine |
AlanineArginineAsparagineAspartic AcidGlutamic AcidGlycineLeucineLysinePhenylalanineProlineTyrosine
New HPLC Amino Acids Separation Compatible With Carbon Dating Technique
Hydroxyproline seems to be the most promising amino acid used in carbon dating when isolated from bone collagen. Separation of amino acids is challenging, especially without the use of ions or inorganic buffers that can interfere with Mass spectrometer (MS) or contaminate the sample with modern carbon. Amino acids are also not retained in reverse-phase chromatography. The ideal solution would be using water only to separate the amino acids. This would allow a direct coupling to MS. We were able to separate hydroxyproline from proline and other simple amino acids like glycine and alanine in HPLC on Newcrom AH column using water only as a mobile phase. Using water also allowed UV detection at 205 nm which can’t be done if using a buffer based on acetic or formic acid.
See more information on radiocarbon dating here.
The same method can be modified to get symmetrical peaks and higher efficiency if a mobile phase with ionic modifier such as formic acid is used.
Condition
Column |
Newcrom AH, 4.6x150 mm, 5 µm, 100A |
Mobile Phase |
MeCN/H2O |
Flow Rate |
1.0 ml/min |
Detection |
UV, 205 nm, CAD |
Description
Class of Compounds
|
Drug, Acid, Hydrophilic, Ionizable, Vitamin, Supplements, Amino acid |
Analyzing Compounds |
Alanine, Glycine, Proline, Hydroxyproline |
AlanineD-AlanineGlycineHydroxyprolineProline