| 1. |
- Bertani, Federico, et al.
(författare)
-
Triptycene-Roofed Quinoxaline Cavitands for the Supramolecular Detection of BTEX in Air
- 2016
-
Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 22, s. 3312-3319
-
Tidskriftsartikel (refereegranskat)abstract
- Two novel triptycene quinoxaline cavitands (DiTriptyQxCav and MonoTriptyQxCav) have been designed, synthesized, and applied in the supramolecular detection of benzene, toluene, ethylbenzene, and xylenes (BTEX) in air. The complexation properties of the two cavitands towards aromatics in the solid state are strengthened by the presence of the triptycene moieties at the upper rim of the tetraquinoxaline walls, promoting the confinement of the aromatic hydrocarbons within the cavity. The two cavitands were used as fiber coatings for solid‐phase microextraction (SPME) BTEX monitoring in air. The best performances in terms of enrichment factors, selectivity, and LOD (limit of detection) values were obtained by using the DiTriptyQxCav coating. The corresponding SPME fiber was successfully tested under real urban monitoring conditions, outperforming the commercial divinylbenzene–Carboxen–polydimethylsiloxane (DVB–CAR–PDMS) fiber in BTEX adsorption.
|
|
| 2. |
- Bianchi, Federica, et al.
(författare)
-
MS-Based Analytical Techniques : Advances in Spray-Based Methods and EI-LC-MS Applications
- 2018
-
Ingår i: Journal of Analytical Methods in Chemistry. - : Hindawi Limited. - 2090-8865 .- 2090-8873. ; 2018
-
Forskningsöversikt (refereegranskat)abstract
- Mass spectrometry is the most powerful technique for the detection and identification of organic compounds. It can provide molecular weight information and a wealth of structural details that give a unique fingerprint for each analyte. Due to these characteristics, mass spectrometry-based analytical methods are showing an increasing interest in the scientific community, especially in food safety, environmental, and forensic investigation areas where the simultaneous detection of targeted and nontargeted compounds represents a key factor. In addition, safety risks can be identified at the early stage through online and real-time analytical methodologies. In this context, several efforts have been made to achieve analytical instrumentation able to perform real-time analysis in the native environment of samples and to generate highly informative spectra. (is review article provides a survey of some instrumental innovations and their applications with particular attention to spray-based MS methods and food analysis issues. The survey will attempt to cover the state of the art from 2012 up to 2017.
|
|
| 3. |
- Bianchi, F., et al.
(författare)
-
Novel sample-substrates for the determination of new psychoactive substances in oral fluid by desorption electrospray ionization-high resolution mass spectrometry
- 2019
-
Ingår i: Talanta. - : Elsevier B.V.. - 0039-9140 .- 1873-3573. ; 202, s. 136-144
-
Tidskriftsartikel (refereegranskat)abstract
- A reliable screening and non invasive method based on the use of microextraction by packed sorbent coupled with desorption electrospray ionization-high resolution mass spectrometry was developed and validated for the detection of new psychoactive substances in oral fluid. The role of different sample substrates in enhancing signal intensity and stability was evaluated by testing the performances of two polylactide-based materials, i.e. non-functionalized and functionalized with carbon nanoparticles, and a silica-based material compared to commercially available polytetrafluorethylene supports. The best results were achieved by using the non-functionalized polylactide substrates to efficiently ionize compounds in positive ionization mode, whereas the silica coating proved to be the best choice for operating in negative ionization mode. LLOQs in the low μg/L, a good precision with CV% always lower than 16% and RR% in the 83(±4)-120(±2)% range, proved the suitability of the developed method for the determination of the analytes in oral fluid. Finally, the method was applied for screening oral fluid samples for the presence of psychoactive substances during private parties, revealing mephedrone in only one sample out of 40 submitted to analysis.
|
|
| 4. |
|
|
| 5. |
- Riboni, Nicolò, 1989-, et al.
(författare)
-
Conformationally blocked quinoxaline cavitand as solid-phase microextraction coating for the selective detection of BTEX in air
- 2016
-
Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 905, s. 79-84
-
Tidskriftsartikel (refereegranskat)abstract
- A tetraquinoxaline cavitand functionalized with methylenoxy bridges at the upper rim is proposed as selective solid-phase microextraction (SPME) coating for the determination of BTEX at trace levels in air. The SPME fibers were characterized in terms of film thickness, morphology, thermal stability and extraction capabilities. An average coating thickness of 35 (±4) μm, a thermal stability up to 350 °C and a good fiber-to-fiber and batch-to-batch repeatability with RSD lower than 15% were obtained. Excellent enrichment factors ranging from 360–700 × 103 were obtained for the investigated compounds. Finally, method validation proved the capabilities of the developed coating for the selective sampling of BTEX, achieving LOD values in the 0.4–1.2 ng m−3 range.
|
|
| 6. |
- Riboni, Nicolò, 1989-
(författare)
-
New Materials and Improved Ambient Techniques in Mass Spectrometry
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mass spectrometry (MS) is used in several fields, e.g. biology, environmental monitoring, medicine and forensics due to excellent qualitative and quantitative capabilities. The development of new instrumental setups and ionization sources is crucial to analyze a variety of compounds at trace levels. The synergy between material science and analytical chemistry allowed the development of new materials characterized by specific features of polarity, porosity and functionalization, able to interact with targeted analytes in complex matrices, resulting in high extraction efficiency even in presence of overwhelming amounts of interfering compounds. New methods based on the use of new materials and MS techniques for analytes extraction and detection have been proposed, providing fast analysis times, enhanced selectivity and increased sensitivity.In this thesis, the development of new materials and setups for mass spectrometric applications is discussed.In Paper I-III the design, synthesis, characterization and evaluation of the analytical performances of four new supramolecular receptors for targeted extraction of benzene, toluene, ethylbenzene and xylenes (BTEX) are reported. The synthesized materials were used as solid-phase microextraction coatings (SPME) for the GC-MS determination of BTEX at trace levels in urban air. In addition, a portable device for in-situ and real-time monitoring of BTEX using these receptors in the preconcentration unit is presented.In Paper IV the development of coated ion sources able to improve the performances of an interface coupling liquid chromatography (LC) and electron ionization (EI), called Direct-EI LC-MS, is discussed. The coatings, obtained by sol-gel technique, were deposited onto commercial stainless steel EI sources to increase the inertness of its vaporization surface.In Paper V, a rapid screening method for the detection of new psychoactive substances (NPS) in oral fluids is presented. New slides based on polylactide (PLLA), carbon particles and silica were tested as probe materials to promote the ionization of the analytes in desorption electrospray ionization – high resolution mass spectrometry (DESI-HRMS). Microextraction by packed sorbent (MEPS) of the analytes from the saliva samples was required due to the high signal suppression. The developed MEPS-DESI-HRMS method was validated and applied for the determination of NPS in road-collected samples.In Paper VI the development of a new setup called solvent assisted paper spray ionization (SAPSI) is reported. This integrated solution allowed the increased data acquisition time and a close control over the ionization conditions. It was applied for the analysis of biomolecules, namely proteins, lipids, glycans, and amyloid peptides/aggregates, in aqueous solution as well as in human serum and cerebrospinal fluid. Different oligomeric species of amyloid aggregates were detected and it was possible to perform real-time monitoring of disaggregation processes. Modified protein species of physiological relevance such as oxidation, cysteinylation, glycosylation and glycation, and adduct formation were identified.In conclusion, the new materials and setups discussed in this thesis allowed the development of selective and sensitive MS methods for the determination of different target compounds in complex matrices at trace levels with reduced sample pretreatment.
|
|
| 7. |
- Riboni, Nicolò, 1989-, et al.
(författare)
-
Sol-gel coated ion sources for liquid chromatography-direct electronionization mass spectrometry
- 2017
-
Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 978, s. 35-41
-
Tidskriftsartikel (refereegranskat)abstract
- Advances in interfacing liquid chromatography and electron ionization mass spectrometry are presented. New ion source coatings synthesized by sol-gel technology were developed and tested as vaporization surfaces in terms of peak intensity, peak width and peak delay for the liquid chromatography-direct electron ionization mass spectrometry (Direct-EI) determination of environmental pollutants like polycyclic aromatic hydrocarbons and steroids. Silica-, titania-, and zirconia-based coatings were sprayed inside the stainless steel ion source and characterized in terms of thermal stability, film thickness and morphology. Negligible weight losses until 350–400 °C were observed for all the materials, with coating thicknesses in the 6 (±1)-11 (±2) μm range for optimal ionization process. The best performances in terms of both peak intensity and peak width were obtained by using the silica-based coating: the detection of the investigated compounds was feasible at low ng μl−1 levels with a good precision (RSD < 9% for polycyclic aromatic hydrocarbons and <11% for hormones).
|
|
| 8. |
- Riboni, Nicoló, et al.
(författare)
-
Solvent-Assisted Paper Spray Ionization Mass Spectrometry (SAPSI-MS) for the Analysis of Biomolecules and Biofluids
- 2019
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Paper Spray Ionization (PSI) is commonly applied for the analysis of small molecules, including drugs, metabolites, and pesticides in biological fluids, due to its high versatility, simplicity, and low costs. In this study, a new setup called Solvent Assisted Paper Spray Ionization (SAPSI), able to increase data acquisition time, signal stability, and repeatability, is proposed to overcome common PSI drawbacks. The setup relies on an integrated solution to provide ionization potential and constant solvent flow to the paper tip. Specifically, the ion source was connected to the instrument fluidics along with the voltage supply systems, ensuring a close control over the ionization conditions. SAPSI was successfully applied for the analysis of different classes of biomolecules: amyloidogenic peptides, proteins, and N-glycans. The prolonged analysis time allowed real-time monitoring of processes taking places on the paper tip, such as amyloid peptides aggregation and disaggregation phenomena. The enhanced signal stability allowed to discriminate protein species characterized by different post translational modifications and adducts with electrophilic compounds, both in aqueous solutions and in biofluids, such as serum and cerebrospinal fluid, without any sample pretreatment. In the next future, application to clinical relevant modifications, could lead to the development of quick and cost-effective diagnostic tools.
|
|
| 9. |
|
|
| 10. |
- Trzciński, Jakub W., et al.
(författare)
-
In Search of the Ultimate Benzene Sensor : The EtQxBox Solution
- 2017
-
Ingår i: ACS Sensors. - : American Chemical Society (ACS). - 2379-3694. ; 2:4, s. 590-598
-
Tidskriftsartikel (refereegranskat)abstract
- In this work we report a comprehensive study leading to the fabrication of a prototype sensor for environmental benzene monitoring. The required high selectivity and ppb-level sensitivity are obtained by coupling a silicon-integrated concentration unit containing the specifically designed EtQxBox cavitand to a miniaturized PID detector. In the resulting stand-alone sensor, the EtQxBox receptor acts at the same time as highly sensitive preconcentrator for BTEX and GC-like separation phase, allowing for the selective desorption of benzene over TEX. The binding energies of the complexes between EtQxBox and BTX are calculated through molecular mechanics calculations. The examination of the corresponding crystal structures confirms the trend determined by computational studies, with the number of C–H···N and CH···π interactions increasing from 6 to 9 along the series from benzene to o-xylene. The analytical performances of EtQxBox are experimentally tested via SPME, using the cavitand as fiber coating for BTEX monitoring in air. The cavitand EFs are noticeably higher than those obtained by using the commercial CAR-DVB-PDMS. The LOD and LOQ are calculated in the ng/m3 range, outperforming the commercial available systems in BTEX adsorption. The desired selective desorption of benzene is achieved by applying a smart temperature program on the EtQxBox mesh, which starts releasing benzene at lower temperatures than TEX, as predicted by the calculated binding energies. The sensor performances are experimentally validated and ppbv level sensitivity toward the carcinogenic target aromatic benzene was demonstrated, as required for environmental benzene exposure monitoring in industrial applications and outdoor environment.
|
|
