Lactic Acid

CAS Number 50-21-5
Molecular Formula C3H6O3
Molecular Weight 90.078 g/mol
LogP -0.720
  • Lactic acid
  • 2-Hydroxypropanoic acid
  • Propanoic acid, 2-hydroxy-
  • 50-21-5
  • Propanoic acid, 2-hydroxy-
  • DL-Lactic Acid
  • (+/-)-Lactic acid
  • 2-Hydroxy-2-methylacetic acid
  • 2-Hydroxypropanoic acid
  • 2-Hydroxypropionic acid
  • Acide lactique
  • acido lactico
  • Chem-Cast
  • Milchsaure
  • Milk acid
  • NSC 367919
  • Propanoic acid,2-hydroxy-,(+-)-
  • Purac FCC 80
  • Purac FCC 88
  • Tonsillosan
  • α-Hydroxypropanoic acid
  • α-Hydroxypropionic acid
  • BRN 5238667
  • EINECS 200-018-0
  • EINECS 209-954-4
  • Ethylidenelactic acid
  • FEMA No. 2611
  • FEMA Number 2611
  • 1-Hydroxyethanecarboxylic acid
  • alpha-Hydroxypropionic acid
  • Lactate
  • Lactic acid USP
  • Lactovagan
  • Ordinary lactic acid
  • Propionic acid, 2-hydroxy-
  • Racemic lactic acid
  • EPA Pesticide Chemical Code 128929
  • Acidum lacticum
  • Aethylidenmilchsaeure
  • (RS)-2-Hydroxypropionsaeure
  • DL-Milchsaeure
  • Kyselina 2-hydroxypropanova
  • Kyselina mlecna
  • UNII-3B8D35Y7S4
  • Cheongin haejanghwan
  • Cheongin samrakhan
  • Cheongin haewoohwan
  • Lacticum acidum
  • 849585-22-4
  • 152-36-3
  • 598-82-3
  • 1334714-39-4


HPLC Separation of Lactic Acid and Its Oligomers

Lactic acid (milk acid) is natural organic acid that plays an important role in biochemical processes. It has carboxylic and hydroxy-groups which upon standing can react with each other and forms dimers, trimers and higher oligomers. Lactic acid is a polar molecule that produces no retention on reversed-phase column. Primesep B2 mixed-mode anion-exchange column is used for separation of lactic acid and its oligomers by combination of weak reversed-phase and anion-exchange mechanisms. Oligomers of lactic acid can be converted to lactic acid by hydrolysis. Primesep B2 column can be used for analysis of lactic acid alone and lactic acid in the mixture of oligomers. Lactates can be monitored by low UV, ELSD or LC/MS. In case of ELSD, CAD or LC/MS, phosphoric acid in the mobile phase needs to be replaced with buffer compatible with these detection techniques (ammonium formate or TFA).

Application Analytes:

Lactic Acid
Lactic Acid Oligomers
Organic Acids

Analysis of Lactic Acid on Primesep D Column

Lactic acid (milk acid) is a hydrophilic acid which plays important role in many bioprocesses. Lactic acid has a tendency to self-condense to form dimers, trimers and high molecular weight oligomers. Lactic acid and it’s oligomers are retained by a combination of weak reversed-phase and weak anion-exchange mechanisms on Primesep D mixed-mode HPLC column. Retention time is controlled by amount of acetonitrile, buffer concentration and buffer pH. Method is compatible with LC/MS and other detection techniques and can be used for analysis of lactic acid in various matrices.


Column Primesep D, 4.6x150 mm, 5 µm, 100A
Mobile Phase MeCN/H2O - 30/70%
Buffer AmAc pH 4.0- 20 mM
Flow Rate 1.0 ml/min
Detection ELSD


Class of Compounds Acid, Hydrophilic, Ionizable
Analyzing Compounds Lactic Acid

Application Analytes:

Lactic Acid
Lactic Acid Oligomers