Amino Acid Testing by HPLC

AAL Amino Acid Testing by HPLC – AAL’s Dietary Supplement labs are capable of testing the amino acid as either basic amino acids or those formed from protein hydrolysis. Proteins are composed of groups of amino acids of different types and percentages. The protein samples are subject to acid hydrolysis and break down into individual amino acids, which react with derivatized chemical agents and convert to stable-chromophore amino acids. These are separated and analyzed by HPLC.

Amino acids are molecules containing an amine NH2-group, a carboxylic COOH-group and a side chain that varies between different amino acids. These groups of amino acids are the basic building blocks in the human body. Amino acids are classified into two main groups: essential and non-essential.

An essential amino acid is an amino acid that cannot be synthesized by our body and therefore must be supplied in the diet. There are eight essential amino acids in the group:

  • Phenylalanine
  • Valine
  • Threonine
  • Tryptophan
  • Isoleucine
  • Methionine
  • Leucine
  • Lysine

Non-essential amino acids are amino acids that can be produced by our body. Their uses and functions in our body are equally important as the limiting amino acids. There are 13 non-essential amino acids:

  • Alanine
  • Arginine
  • Cysteine
  • Cystine
  • Glutamine
  • Glutathione
  • Glycine
  • Histidine
  • Serine
  • Tyrosine
  • Hydroxyproline
  • Asparagine
  • Proline

The US Pharmacopeia Dietary Supplement Chapter lists detailed test methods on each individual amino acid ingredient as follows:

  • Identification perform by FTIR
  • Chromatographic impurities performed by TLC–ninhydrin method
  • Potency of raw material assay are performed by titration


Summary on Finished Goods Amino Acid Testing

The amino acids in finished goods such as tablets, capsules, powders, liquid syrups are hydrolyzed to break down into amino acids and are analyzed by high performance liquid chromatography (HPLC).


List of raw material dietary supplement nutrient  and amino acid  in USP monograph identification and potency:

Acetyl Tyrosine Glucosamine Methionine
Alanine Glutamine Methylsulfonylmethane
Alanine Glycine Phenylalanine
Arginine Histidine Proline
Aspartic Acid Isoleucine Selenomethionine
Choline Bitartrate Leucine Serine
Chondroitin Ssulfate L-carnitine Threonine
Cysteine Lipoic Acid Tyrosine
Cystine Lysine CoQ10 (Ubidecarenone)

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