Monographs (EP and USP)

Some applications for capillary electrophoresis are described in EP or USP. Several of these applications are presented in the following chapters.

Betadex (SBE-β-CD)

  • Separation: CZE
  • Electrolyte: benzoic acid with Tris
  • Capillary: fused silica, 50 µm ID, 50 cm in total
  • Temperature: 25°C
  • Injection: 10 s, 34 mbar
  • Detection: indirect UV, 205 nm
  • Description: This method describes the determination of the distribution of the substitution of sulfobutylether-β-cyclodextrin (SBE-β-CD). Ten different levels of substitution are checked. The resulting peak areas are normalized and evaluated against the defined values.
SBE-B-CD, EP, USP

Betadex according USP

Download: Betadex.pdf

S-Ropivacaine hydrochloride monohydrate – Determination of enantiomeric purity

  • Separation: MEKC
  • Electrolyte: Heptakis-(2,6-di-O-methyl)-β-cyclodextrin, phosphoric acid and Triethanolamine, pH 3.0
  • Capillary: fused silica, 50 µm ID, 81,5 cm in total
  • Temperature: 30°C
  • Injection: 10 s, 50 mbar
  • Detection: direct UV, 206 nm
  • Description: The aim of the analysis is the determination of the enantiomeric purity of S-ropivacain with regard to R-ropivacain. For SST the resolution and the limit of detection of the enantiomers is determined.
Ropivacain-SST

Ropivacaine-SST

Download: Ropivacain-SST.pdf

S-Ropivacaine hydrochloride monohydrate – Sample

  • Separation: MEKC
  • Electrolyte: Heptakis-(2,6-di-O-methyl)-β-cyclodextrin, phosphoric acid and Triethanolamine, pH 3.0
  • Capillary: fused silica, 50 µm ID, 81,5 cm in total
  • Temperature: 30°C
  • Injection: 10 s, 50 mbar
  • Detection: direct UV, 206 nm
  • Description: For the sample the enantiomeric purity of S-ropivacain with regard to R-ropivacain was tested.
Ropivacain-Probe

Ropivacaine-Sample

Download: Ropivacain-Probe.pdf

Somatropin – Determination of purity

  • Separation: CZE
  • Electrolyte: Diammoniumhydrogenphosphate with phosphoric acid, pH 6,0
  • Capillary: fused silica, 50 µm ID, 64,5 cm in total
  • Temperature: 30°C
  • Injection: 4 s, 50 mbar
  • Detection: direct UV, 200 nm
  • Description: In total four impurities are recorded. On the basis of the SST it has to be proved that impurity I1 and I2 migrate before the main peak and I3 and I4 migrate after the main peak. Impurity I4 is the deamidated form, which migrates as a double peak. The assignment is made by means of the relative migration times.
Somatropin-SST

Somatropin-SST

Download: Somatropin-SST

 

Glutathione – Purity

Synonyms:

  • 2-Amino-5-{[1-((carboxymethyl)amino)-1-oxo-3-sulfanylprop-2-yl]amino}-5-oxovaleriansäure
  • γ-L-Glutamyl-L-cysteinyl-glycin
  • GSH, ECG
  • [70-18-8]

Glutathione (GSH) is an antioxidant in plants, animals, fungi, and some bacteria and archaea. Glutathione is capable of preventing damage to important cellular components caused by reactive oxygen species such as free radicals, peroxides, lipid peroxides, and heavy metals. Because of its antioxidant effect, glutathione is used as a dietary supplement.

  • CE mode: CZE
  • Electrolyte: Phosphate 50 mM, pH 1,8 (adjusted with 85% H3PO4 to fulfill the SST)
  • Capillary: fused silica, 75 µm ID, 64 cm total length
  • Temperature: 25°C
  • Injection: 5 s, 50 mbar
  • Detection: direkte UV, 200 nm
  • Separation: 20 kV

Method description:
The method corresponds to the European Pharmacopoeia, monograph number 1670. It is used for testing the purity of glutathione by determining the related substances L-cysteinylglycine, L-cysteine, L-glutathione oxidized, L-y-glutamyl-L-cysteine and unspecified impurities. The quantification is performed using L-phenylalanine as internal standard.

Glutathion-SST

Glutathion-SST

Download: Glutathione – purity