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Samarasinghe I, Attygalle AB. Impact of Ambient Vapors on Spectra of 4-Nitroaniline Recorded under Atmospheric Solids Analysis Probe (ASAP) Mass Spectrometric Conditions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:205-217. [PMID: 36689202 DOI: 10.1021/jasms.2c00259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Thermally desorbed 4-nitroaniline (4-NA), upon atmospheric pressure chemical ionization (APCI), generates gaseous ions for its protonated species. The APCI mass spectrum recorded under mild in-source ion-activating conditions from 4-NA showed a peak at m/z 139, whereas that acquired under high ion-activating conditions showed two additional peaks at m/z 122 (•OH loss) and 92 (•NO loss). The spectrum changed instantaneously when acetonitrile vapor was introduced to the source. In the new spectrum, both m/z 122 and 92 peaks were absent, while a new peak appeared at m/z 93. Ion-mobility separation carried out with the m/z 139 ion revealed that the initial ion represented the thermodynamically favored nitro-protonated tautomer. The ion population changed to an ensemble dominated by the less-favored amino-protomer when acetonitrile vapor was introduced to the ion source. The amino-protomer, upon collisional activation, loses •NO2 to generate an m/z 93 ion, which was confirmed to be the 4-dehydroanilinium ion. Ion mobility provided a practical way to monitor the changes secured by acetonitrile vapor because the two protomers showed different arrival times. Under spray-ionization conditions, the formation of the thermodynamically less favored protomer has been attributed to kinetic trapping. Our study demonstrated that the less favored amino-protomer could be generated by introducing acetonitrile vapor under nonspray conditions. Apparently, under APCI conditions, protonated water vapor attaches to the nitro group to generate a proton-bound heterodimer, which upon activation dissociates to yield the nitro-protomer. In contrast, protonated acetonitrile makes a tighter complex preferentially with the amino group, which upon activation breaks to the amino-protomer.
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Affiliation(s)
- Ishira Samarasinghe
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey07030, United States
| | - Athula B Attygalle
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey07030, United States
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Pizzo JS, Cruz VHM, Manin LP, Santos PDS, Silva GR, Souza PM, Figueiredo AL, Santos OO, Visentainer JV. First report on quality and purity assessment of sweet almond oil in Brazilian body oils by gas chromatography and mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2023; 58:e4900. [PMID: 36688359 DOI: 10.1002/jms.4900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/16/2022] [Accepted: 09/21/2022] [Indexed: 06/17/2023]
Abstract
Sweet almond oil is a raw material with high-added value used in different products. Then, the aim of this study is to evaluate the quality and purity of 10 body oils based on sweet almond oils currently available in the Brazilian market. Fatty acid composition and triacylglycerol (TAG) profile were determined by gas chromatography with flame ionization detector (GC-FID) and atmospheric solids analysis probe mass spectrometry (ASAP-MS), respectively. The authenticity of samples was assessed using an analytical curve equation. Soybean oil was chosen as the adulterant because it is the cheapest vegetable oil commercialized in Brazil. Hierarchical clustering analysis (HCA) in conjunction with ASAP-MS classified product samples according to the type of vegetable oil (soybean and sweet almond oils). The addition of soybean oil (8.79% to 99.70%) was confirmed in samples. However, only two samples stated in their label the presence of soybean oil as an ingredient. These findings highlight the need for better oversight by regulatory bodies to ensure that consumers acquire high quality and authentic products based on equally high quality and purity of sweet almond oils.
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Affiliation(s)
- Jessica S Pizzo
- Department of Chemistry, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
| | - Victor H M Cruz
- Department of Chemistry, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
| | - Luciana P Manin
- Post-Graduate Program in Food Science, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
| | - Patricia D S Santos
- Department of Chemistry, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
| | - Geovane R Silva
- Department of Chemistry, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
| | - Patrícia M Souza
- Department of Chemistry, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
| | - Alisson L Figueiredo
- Department of Chemistry, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
| | - Oscar O Santos
- Department of Chemistry, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
| | - Jesuí V Visentainer
- Department of Chemistry, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
- Post-Graduate Program in Food Science, State University of Maringá (UEM), Maringá, Paraná, 87020-900, Brazil
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Creydt M, Fischer M. Food metabolomics: Latest hardware-developments for nontargeted food authenticity and food safety testing. Electrophoresis 2022; 43:2334-2350. [PMID: 36104152 DOI: 10.1002/elps.202200126] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/10/2022] [Accepted: 09/05/2022] [Indexed: 12/14/2022]
Abstract
The analytical requirements for food testing have increased significantly in recent years. On the one hand, because food fraud is becoming an ever-greater challenge worldwide, and on the other hand because food safety is often difficult to monitor due to the far-reaching trade chains. In addition, the expectations of consumers on the quality of food have increased, and they are demanding extensive information. Cutting-edge analytical methods are required to meet these demands. In this context, non-targeted metabolomics strategies using mass and nuclear magnetic resonance spectrometers (mass spectrometry [MS]) have proven to be very suitable. MS-based approaches are of particular importance as they provide a comparatively high analytical coverage of the metabolome. Accordingly, the efficiency to address even challenging issues is high. A variety of hardware developments, which are explained in this review, have contributed to these advances. In addition, the potential of future developments is highlighted, some of which are currently not yet commercially available or only used to a comparatively small extent but are expected to gain in importance in the coming years.
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Affiliation(s)
- Marina Creydt
- Hamburg School of Food Science - Institute of Food Chemistry, University of Hamburg, Hamburg, Germany
| | - Markus Fischer
- Hamburg School of Food Science - Institute of Food Chemistry, University of Hamburg, Hamburg, Germany
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