Phosphoric Acid

CAS Number 7664-38-2
Molecular Formula H3O4P
Molecular Weight 97.994 g/mol
LogP -0.770
  • Phosphoric acid
  • 7664-38-2
  • Phosphoric acid Divosan X-Tend formulation
  • 3M Etching Liquid
  • Acide orthophosphorique
  • acido ortofosforico
  • Amberphos 54
  • Conditioner 36
  • Etchalite
  • Kerr Etchant
  • K-etchant
  • Mikro Klene DF
  • NSC 80804
  • orthophosphoric acid
  • orthophosphoric acid H3O4P
  • Orthophosphorsaure
  • Panavia Etching Agent
  • Phosphoric Acid AR
  • Total Etch
  • Ultraetch
  • Ultra-Etch Gel
  • UN 1805
  • UN3453
  • Uni-Etch
  • WC-Reiniger
  • Caswell No. 662
  • EINECS 231-633-2
  • EPA Pesticide Chemical Code 076001
  • FEMA No. 2900
  • o-Phosphoric acid
  • Phosphoric acid, ortho-
  • Acido fosforico
  • Fosforzuuroplossingen
  • UNII-E4GA8884NN
  • Phosphoricum acidum
  • Acide phosphorique (FRENCH)
  • Acido fosforico [Italian]
  • Diphosphate tetrasodium
  • Fosforzuuroplossingen [Dutch]
  • H3PO4
  • Marphos
  • NFB
  • Ortho- phosphoric acid
  • Phosphate
  • Phosphoric acid
  • Phosphoric acid (ACD/Name 4.0)
  • Phosphorsaeure
  • Phosphorsaeureloesungen
  • Phosphorsaeureloesungen [German]
  • Sodium Pyrophosphate
  • Sodium pyrophosphate decahydrate
  • Sodium pyrophosphate decahydrate BioChemica
  • Sonac
  • Tetra-Sodium pyrophosphate
  • Tetrasodium Pyrophosphate Decahydrate
  • Tetrasodium pyrophosphate 10-hydrate
  • White phosphoric acid
  • [PO(OH)3]
  • acide phosphorique
  • acidum phosphoricum
  • 1021417-41-3
  • 1053657-23-0
  • 1196963-54-8
  • 178560-73-1
  • 28602-75-7
  • 959699-83-3


HPLC Analysis of Basic Drugs and Acidic Counter-Ions by Mixed-Mode Chromatography
The majority of drugs in the pharmaceutical industry are administered in salt form. The presence of two counter-ions very often necessitates the use of two methods. The nature of these counterparts in drugs can be an inorganic cation and organic acid, inorganic anion and organic base, and organic cation and organic anion. Furthermore, the properties of the molecules will result in a differing stoichiometry. The task of simultaneous quantitation of counter-ions can be achieved by using mixed-mode columns. The general approach for analysis is based on properties of corresponding counter-ions. Hydrophobic basic drugs, like dextromethorphan, verapamil, trimipramine, and corresponding acidic counter-ions (chloride, chlorate, bromide, bromate, perchlorate, maleate, fumarate,tartrate, succinate, phosphate, citrate, benzosulfonate, toleuensulfonate) can be separated and quantitated in the same run on reversed-phase anion-exchange column. Basic hydrophobic drugs are retained by the reversed-phase mechanism, and counter-ions are retained by the reversed-phase and anion-exchange mechanism. Some polar counter-ions are retained only by the anion-exchange mechanism. Retention time and selectivity of HPLC separation of drugs and counter-ions can be achieved by changing the amount of acetonitrile and the amount of ions in the mobile phase. The detection technique depends on the properties of the counter-ions. In case of low or no UV activity, ELSD can be employed if the counter-ion forms a non-volatile salt with the mobile phase additive (ammonium formate). This HPLC method can be used for simultaneous quantitation of other basic drugs and counter-ions. The presence of two mechanisms of retention allows control over retention times of drug and counter-ion independently, and even allows a change of order of elution when necessary.


Column Primesep D , 4.6x150 mm, 5 µm, 100A
Mobile Phase MeCN/H2O
Buffer AmFm pH 3.0
Flow Rate 1.0 ml/min
Detection ELSD, UV 270


Class of Compounds Ions, Hydrophilic, Hydrophobic, Base, Acids, Ionizable
Analyzing Compounds Sodium Chloride, Sodium chloride, Sodium Chlorate, Sodium bromide, Sodium bromate, Perchloric Acid, Maleic Acid, Fumaric Acid, Tartaric Acid, Succinic Acid, Phosphoric Acid, Citric acid, Benzosulfonic acid,  Dextromethorphan, Verapamil, Trimipramine

Application Analytes:

Benzenesulfonic Acid
Citric Acid
Fumaric Acid
Maleic Acid
Organic Acids
Phosphoric Acid
Succinic Acid
Tartaric Acid
p-Toluenesulfonic Acid (PTSA)

HPLC Separation of Phosphorous and Phosphoric Acids
  Application Notes: Phosphorus and phosphoric acid were separated on Obelisc N and Primesep D columns. On Obelisc N both acids retained by combination of HILIC and anion-exchange mechanisms. OnPrimesep D these inogranic acids are retained by anion-exchange mechanism. Both columns and methods can be used for analysis of hydrophilic organic and inorganic acids with multi-mode or single mode approach Application Columns: Primesep D, Obelisc N Application compounds: Phosphorous Acid, Phosphoric Acid Detection technique: UV, LC/MS, ELSD/CAD  

Condition 1

Column Primesep D, 3.2x150 mm, 5 µm, 100A
Mobile Phase MeCN
Buffer AmFm
Flow Rate 0.5 ml/min
Detection ELCD

Condition 2

Column Obelisc N, 4.6x50 mm, 5 µm, 100A
Mobile Phase  MeCN
Buffer AmFm
Flow Rate 0.5 ml/min
Detection ELSD


Class of Compounds  Acid, Fungicide,  Hydrophilic, Ionizable
Analyzing Compounds Phosphorous Acid,  Phosphoric Acids

Application Analytes:

Phosphoric Acid
Phosphorous acid