**Acknowledgement**

This study was supported by National Grant - IDEI-PCE Exploratory Research Program - Project no. **341-/01.10.2011 - Immunomodulante Fluoroglycopeptide Molecular Architectures**.

## **6. References**

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144 Analytical Chemistry

**Figure 4.** Valine MS-specta

**Author details** 

*Timisoara, Romania* 

**6. References** 

**Acknowledgement** 

Ion Neda, Paulina Vlazan, Raluca Oana Pop,

Paula Sfarloaga, Ioan Grozescu and Adina-Elena Segneanu

useful for the structural elucidation of organic compounds and for peptide or oligonucleotide sequencing. The major advantadge in using MS is due to the need for very small amounts of sample (ng to pg). A disadvantage of conventional ionization methods (e.g., electron impact, API) is that they are limited to compounds with sufficient volatility, polarity and MW. Volatility can be increased by chemical modifications (derivatizations, such as: methylation, trimethylsilylation or trifluoro-acetylation). For peptides, there has been developed certain new, very efficient techniques, such as: electrospray ionization (ESI)

In the next Figure 4, is presented the mass spectrum of pure valine, recorded on a Bruker

257.7

+MS, 9.5-9.6min #(342-344)

NMR spectroscopy offers the most useful and valuable information about the structure of perhaps any natural product. The method has the advantage of excellent reproducibility. Even though it is considered to be one of the more expensive techniques, NMR is relatively

50 75 100 125 150 175 200 225 250 275 m/z

cheap, fast sensitive and easily used as a routine application for amino acid analysis.

*National Institute for Research and Development in Electrochemistry and Condensed Matter,* 

This study was supported by National Grant - IDEI-PCE Exploratory Research Program - Project no. **341-/01.10.2011 - Immunomodulante Fluoroglycopeptide Molecular Architectures**.

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Daltonics High Capacity Ion Trap Ultra (HCT Ultra, PTM discovery) instrument.

and matrix-assisted laser desorption ionization (MALDI).

117.7


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