Validation of Breast Cancer Margins by Tissue Spray Mass Spectrometry.

Current methods for the intraoperative determination of breast cancer margins commonly suffer from the insufficient accuracy, specificity and/or low speed of analysis, increasing the time and cost of operation as well the risk of cancer recurrence. The purpose of this study is to develop a method for the rapid and accurate determination of breast cancer margins using direct molecular profiling by mass spectrometry (MS). Direct molecular fingerprinting of tiny pieces of breast tissue (approximately 1 × 1 × 1 mm) is performed using a home-built tissue spray ionization source installed on a Maxis Impact quadrupole time-of-flight mass spectrometer (qTOF MS) (Bruker Daltonics, Hamburg, Germany).

Remote detection of explosives using field asymmetric ion mobility spectrometer installed on multicopter.

The detection of explosives and drugs in hard-to-reach places is a considerable challenge. We report the development and initial experimental characterization of the air analysis system that includes Field Asymmetric Ion Mobility Spectrometer, array of the semiconductor gas sensors and is installed on multicopter. The system was developed based on the commercially available DJI Matrix 100 platform.

Thermal desorption combined with atmospheric pressure photo ionization for the analysis of volatile compounds and its possible applications.

We report an approach to study volatile organic compounds based on thermal desorption combined with atmospheric pressure photo ionization. The approach allows the sequential evaporation of different fractions of the sample, which simplifies the mass spectrum. We have applied the developed method for the detection of petroleum in vegetable oil.

Letter: Supermetallization of peptides and proteins with tetravalent metal Th(IV).

Supermetallization is the recently observed phenomenon of the formation of complex ions of peptide-metal in the gas phase when the peptide accepts an unexpectedly large number of metal atoms. It has been found that supermetallization takes place during electrospray ionization when charged droplets are evaporating at relatively high temperature (ca 400°C). In the present paper, we demonstrate supermetallized complexes of small protein ubiquitin and two peptides with Th(IV).

Observation of the multiple halogenation of peptides in the electrospray ionization source.

The chlorination of peptides and proteins is an important posttranslational modification, which is a physiological signature of an enzyme myeloperoxidase and can serve as a potential biomarker of some diseases (Parkinson's disease, Alzheimer's disease, etc.). The quantification of the chlorinated peptides has been very challenging in part due to their low levels and artifacts associated with sample preparation.

Separation of tautomeric forms of [2-nitrophloroglucinol-H]- by an in-electrospray ionization source hydrogen/deuterium exchange approach.

Here we report the observation that, depending on the solvent used for the electrospray, 2-nitrophloroglucinol undergoes a deprotona- tion from different sites forming two tautomeric gas phase ions. Those ions differ bythe collision-induced dissociation [CID] spectra and by the gas phase hydrogen/deuterium (H/D) exchange kinetic. We performed H/D exchange in the electrospray ionization (ESI) source by saturation ESI region with vapors of deuterated solvent (D20).