Synthetic & small organic compounds

If possible, submit samples as solids. Usually, microgram amounts (100-200µg) are sufficient. An appropriate solubility information should be noted in “comments” in the sample submission form. If samples are provided in solution, please note the following instructions.

Solvents

  • In general, aqueous solvents are preferred.
  • Viscous solvents should be avoided, including DMSO, DMF and THF.
  • Hydrocarbon solvents, such as hexane, are not practicable for ESI, but can be used for MALDI analysis.
  • Please specify if particular solvents should not be used.
  • Two MALDI matrices (HCCA and DHB) are available in the facility. If your compound needs a different matrix, you have to provide it together with your sample.
  • Please indicate on the sample submission form, which molecular weight you expect.

Concentration & Volume

  • Good quality spectra can typically be obtained from samples at 20-50 micromolar concentrations (e.g. 20-50 micrograms/mL for a compound of MW 1000). The volume should be 20µl for MALDI-MS or 100µl for ESI-MS.

Reactivity

  • Please indicate if the compound is sensitive to acidic or basic conditions, as small amounts of acid (formic, acetic) or base (ammonium hydroxide, triethylamine) are normally added in order to enhance sample ionization.