**Author details**

*Mass Spectrometry in Life Sciences and Clinical Laboratory*

spectroscopy and LC-QTOF-MS.

*MALDI-PSD analysis of BPC 157.*

as small peptides, such as ipamorelin.

**4. Conclusions**

**Figure 11.**

**Abbreviations**

ACN Acetonitrile Aib Aminobutyric acid

BPC 157 was recently identified in several confiscated vials for injection. The identification was carried out by MALDI in both PSD and reflectron modes (**Figure 11**). The amino acid sequence of the peptide was confirmed by NMR

The proposed methods, based on PMF by MALDI-TOF-MS as well as analysis with DICZE, provided an efficient procedure for the identification of peptides and proteins in illegally distributed samples. The use of trypsin as a proteolytic enzyme generated peptide fragments which covered 40 to 80% of the amino acid sequences of the analyzed proteins. The presence of a signature peptide in the peptide map facilitated the analyte identification considerably. MALDI-TOF-MS was also applied in the PSD mode for the amino acid sequencing of selected tryptic peptides as well

The double-injection CE method provided complementary information on the native protein in the presence of a reference standard. This provided the possibility of performing a comparison between the electrophoretic patterns of the reference standard and the analyte to be identified. In addition, the double-injection based identifications were carried out by comparing the corrected migration time of the

analyte and the observed migration time of the reference standard.

ACHCA α-cyano-4-hydroxycinnamic acid

BPC Body protecting compound

**42**

Ahmad Amini1 \*, Torgny Rundlöf<sup>1</sup> , Henrik Lodén1,2, Johan A. Carlsson1 , Martin Lavén1 , Ezra Mulugeta1 , Karin Björk3 , Torbjörn Arvidsson1 , Iréne Agerkvist1 and Anette Perolari1

1 Swedish Medical Products Agency, Dag Hammarskjölds väg, Uppsala, Sweden

2 Medical Mass Spectrometry Imaging, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden

3 Swedish Customs Laboratory, Solna, Sweden

\*Address all correspondence to: ahmad.amini@lakemedelsverket.se

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
