Water Content

The amount of water in solids is an important parameter in many fields – e.g. in the determination of the content of synthetic peptides where the results are based on amino acid analysis, the counter ion determination, the content of residual organic solvents and the water content. Both the synthesis strategy and the final dosage are dependent upon these values.

METHOD

SOP C.28.1.

In contrast to the indirect methods of water determination whereby products of reaction with water are quantified (e.g. Karl-Fischer-Titration), our proprietary analytical approach measures water directly and requires as little as 1 mg of sample for a single analysis.

After thermal desorption, water is separated from other volatile compounds and is detected quantitatively. Quantitation is performed by the external standard method. The sample is pre-conditioned overnight in a desiccator at ambient conditions over silica gel before analysis to remove surface-water through environmental variances.

We highly recommend to perform analysis in duplicate in order to account for factors such as sample inhomogeneity across e.g. a lyophilisate.

SPECIFICATIONS

  • generic validation
  • Range: 0.4% to 24%
  • LOD: 0.1%
  • LOQ: 0.4%
  • SD: 5% for a water content of 2%
  • RSD: @10% water (n=6): ≤ 8%

REPORTED RESULTS

  • Water content in %

SAMPLE REQUIREMENTS

  • 3 mg (duplicate analysis) – analysis in duplicate is highly recommended
  • solid form (e.g. powdery lyophilisate)
  • stated sample quantities must be easily accessible e.g. by spatula. 

ADVANTAGES

  • low sample requirement of only 3 mg for an analysis in duplicate
  • determination of water is not interfered by other hydroxyl-containing components
  • other volatile components do not falsify the results

ADDITIONAL SERVICES

  • Expanded report can be offered
  • please contact us for a substance specific validation
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