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Garcia MM, Wrobel K, Barrientos EY, Escobosa ARC, Serrano O, Donis IE, Wrobel K. Determination of copper and lead in tequila by conventional matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and partial least squares regression. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:2174-2184. [PMID: 30280437 DOI: 10.1002/rcm.8297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/08/2018] [Accepted: 09/26/2018] [Indexed: 06/08/2023]
Abstract
RATIONALE Quantification of small molecules by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is challenging yet attractive, due to micro-scale procedural simplicity, high throughput and lack of memory effects. Since these features are important while analyzing trace elements in quality control schemes, MALDI-TOFMS was used for the determination of copper (Cu) and lead (Pb) in tequila with quantification carried out by partial least squares regression (PLS2) and by univariate calibration (UC). METHODS In the proposed procedure, Bi(III) was added as internal standard (IS), diethyldithiocarbamate complexes were formed (pH 7.4) and extracted into chloroform; after solvent evaporation and re-constitution in acetonitrile, the sample was co-crystallized with α-cyano-4-hydroxycinnamic acid on a steel target. From the acquired mass spectra, UC was performed using IS-normalized signals of the monoisotopic ions of analytes, and the m/z range 350-513 was used for PLS2. Accuracy was tested by recovery experiments and by inductively coupled plasma (ICP)-MS analysis. RESULTS When compared with direct analyte signal measurements, application of IS yielded enhanced analytical performance using either UC or PLS2; the method quantification limits were: 11.1 μg L-1 , 23.4 μg L-1 for Cu and 89.8 μg L-1 , 97.1 μg L-1 for Pb, respectively. In tequila, MALDI-TOFMS and ICP-MS provided consistent results for Cu (165-2599 μg L-1 ); Pb was not detected in any sample by MALDI-TOFMS, yet recoveries obtained after standard addition were indicative of acceptable accuracy (400 μg L-1 Pb added; recoveries: 91.2-108% for UC and 98.8-120% for PLS2). CONCLUSIONS New experimental evidence has been provided supporting the inclusion of trace metals quantification within a range of MALDI-TOFMS applications. Slightly better results were obtained for UC as compared with PLS2 yet both methods can be recommended for testing the compliance of Cu and Pb levels with Official Mexican Norm. Of note, while using PLS2, there is no need for signal integration nor for IS normalization.
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Affiliation(s)
- Manuel Mendez Garcia
- Department of Chemistry, University of Guanajuato, L de Retana N°5, 36000, Guanajuato, Mexico
| | - Kazimierz Wrobel
- Department of Chemistry, University of Guanajuato, L de Retana N°5, 36000, Guanajuato, Mexico
| | - Eunice Yanez Barrientos
- Department of Chemistry, University of Guanajuato, L de Retana N°5, 36000, Guanajuato, Mexico
| | | | - Oracio Serrano
- Department of Chemistry, University of Guanajuato, L de Retana N°5, 36000, Guanajuato, Mexico
| | - Israel Enciso Donis
- Department of Chemistry, University of Guanajuato, L de Retana N°5, 36000, Guanajuato, Mexico
| | - Katarzyna Wrobel
- Department of Chemistry, University of Guanajuato, L de Retana N°5, 36000, Guanajuato, Mexico
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Garcia MM, Wrobel K, Segovia ASR, Barrientos EY, Escobosa ARC, Serrano O, Aguilar FJA, Wrobel K. Application of MALDI-TOFMS Combined with Partial Least Square Regression for the Determination of Mercury and Copper in Canned Tuna, Using Dithizone as the Complexing Agent and Ag(I) as Internal Standard. FOOD ANAL METHOD 2018. [DOI: 10.1007/s12161-018-1272-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Donnici CL, Nogueira LJ, Araujo MH, Oliveira SR, Magalhães TFF, Lopes MTP, Araújo e Silva AC, Ferreira AMDC, Martins CVB, de Resende Stoianoff MA. In vitro studies of the activity of dithiocarbamate organoruthenium complexes against clinically relevant fungal pathogens. Molecules 2014; 19:5402-20. [PMID: 24879585 PMCID: PMC6270662 DOI: 10.3390/molecules19045402] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 04/17/2014] [Accepted: 04/22/2014] [Indexed: 11/16/2022] Open
Abstract
The in vitro antifungal activity of nine dirutheniumpentadithiocarbamate complexes C1-C9 was investigated and assessed for its activity against four different fungal species with clinical interest and related to invasive fungal infections (IFIs), such as Candida spp. [C. albicans (two clinical isolates), C. glabrata, C. krusei, C. parapsolisis, C. tropicalis, C.dubliniensis (six clinical isolates)], Paracoccidioides brasiliensis (seven clinical isolates), Cryptococcus neoformans and Sporothrix schenckii. All synthesized complexes C1-C9 and also the free ligands L1-L9 were submitted to in vitro tests against those fungi and the results are very promising, since some of the obtained MIC (minimal inhibitory concentration) values were very low (from 10-6 mol mL-1 to 10-8 mol mL-1) against all investigated clinically relevant fungal pathogens, except for C. glabrata, that the MIC values are close to the ones obtained for fluconazole, the standard antifungal agent tested. Preliminary structure-activity relations (SAR) might be suggested and a strong influence from steric and lipophilic parameters in the antifungal activity can be noticed. Cytotoxicity assays (IC50) showed that the complexes are not as toxic (IC50 values are much higher-30 to 200 fold-than MIC values). These ruthenium complexes are very promising lead compounds for novel antifungal drug development, especially in IFIs, one of most harmful emerging infection diseases (EIDs).
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Affiliation(s)
- Claudio L Donnici
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, CEP 31270-901, Belo Horizonte, MG, Brazil.
| | - Luciano J Nogueira
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, CEP 31270-901, Belo Horizonte, MG, Brazil
| | - Maria Helena Araujo
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, CEP 31270-901, Belo Horizonte, MG, Brazil
| | - Sheila Rodrigues Oliveira
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, CEP 31270-901, Belo Horizonte, MG, Brazil
| | - Thais F F Magalhães
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, CEP 31270-901, Belo Horizonte, MG, Brazil
| | - Miriam T P Lopes
- Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, CEP 31270-901, Belo Horizonte, MG, Brazil
| | - Ana Cândida Araújo e Silva
- Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, CEP 31270-901, Belo Horizonte, MG, Brazil
| | - Ana Maria da Costa Ferreira
- Instituto de Química da Universidade de São Paulo, Av. Lineu Prestes, 748, CEP 05508-900, São Paulo, SP, Brazil
| | - Cleide V B Martins
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, CEP 31270-901, Belo Horizonte, MG, Brazil
| | - Maria A de Resende Stoianoff
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, CEP 31270-901, Belo Horizonte, MG, Brazil
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