RESUMO
In this study, a molecularly imprinted polymer-coated probe electrospray ionization mass spectrometry (MIPCPESI-MS) method was developed for detection of phorbol esters (PEs) and deoxyphorbol metabolites in Jatropha curcas leaves. Such an approach was established by sticking on a metallic needle a molecularly imprinted polymer to particularly design a MIP-coated probe for selective sampling and ionization of PEs and deoxyphorbol metabolites. By a subsequent application of a high voltage and methanol, as spray solvent, ESI was generated for direct and rapid analysis under ambient and open-air conditions. MIP-coated probe exhibited a high sampling capacity of the PEs and its metabolites in methanolic extracts of J. curcas leaves compared with the non-imprinted polymer (NIP)-coated probe. MIPCPESI-MS allowed the detection of phorbol 12,13-diacetate (PDA) from J. curcas leaves with minimal sample preparation, and with detection limit and quantification reaching 0.28 µg/mL and 0.92 µg/mL, respectively. Also, good linearity was obtained with R2 > 0.99 and precision and accuracy values between 4.06-13.49% and - 1.60 to - 15.26%, respectively. The current method was successfully applied to screening methanolic extracts of six different J. curcas leaf genotypes (three toxic and three non-toxic). PDA and three PE deoxyphorbol metabolites were identified only from toxic genotypes, in which PDA was determined with concentration ranging from 222.19 ± 23.55 to 528.23 ± 19.72 µg/g. All these findings support that the MIPCPESI-MS method developed here has a high potential for the analysis of PEs in plant extracts enabling differentiation of toxic and non-toxic genotypes earlier in the leaves.
Assuntos
Jatropha/química , Impressão Molecular/métodos , Ésteres de Forbol/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Limite de Detecção , Modelos Lineares , Compostos Fitoquímicos/química , Polímeros , Reprodutibilidade dos TestesRESUMO
This study proposes a new direct and fast method of analysis employing paper spray mass spectrometry (PS-MS). The paper used in the proposed method was modified with molecularly imprinted polymers (MIP) to create a specific site for cocaine analysis in oral fluid. MIP membrane was successfully synthetized and employed. The developed method showed to be linear in a concentration range from LOQ to 100 ng mL-1. The experimental value of LOQ obtained was 1 ng mL-1. The inter-day and intra-day precision and accuracy of the PS-MS method presented values lower than 15%. The total recoveries were also evaluated. The PS-MS method for the analysis of cocaine in oral fluid showed to be very promising and the validation parameters showed a good correlation with the literature. Graphical abstract á .
Assuntos
Cocaína/análise , Drogas Ilícitas/análise , Impressão Molecular , Saliva/química , Microextração em Fase Sólida/métodos , Detecção do Abuso de Substâncias/métodos , Espectrometria de Massas em Tandem/métodos , Desenho de Equipamento , Humanos , Limite de Detecção , Papel , Polímeros/química , Microextração em Fase Sólida/instrumentação , Detecção do Abuso de Substâncias/instrumentação , Espectrometria de Massas em Tandem/instrumentaçãoRESUMO
Thin layer chromatography (TLC) is a simple and inexpensive type of chromatography that is extensively used in forensic laboratories for drugs of abuse analysis. In this work, TLC is optimized to analyze cocaine and its adulterants (caffeine, benzocaine, lidocaine and phenacetin) in which the sensitivity (visual determination of LOD from 0.5 to 14mgmL(-1)) and the selectivity (from the study of three different eluents: CHCl3:CH3OH:HCOOHglacial (75:20:5v%), (C2H5)2O:CHCl3 (50:50v%) and CH3OH:NH4OH (100:1.5v%)) were evaluated. Aiming to improve these figures of merit, the TLC spots were identified and quantified (linearity with R(2)>0.98) by the paper spray ionization mass spectrometry (PS-MS), reaching now lower LOD values (>1.0µgmL(-1)). The method developed in this work open up perspective of enhancing the reliability of traditional and routine TLC analysis employed in the criminal expertise units. Higher sensitivity, selectivity and rapidity can be provided in forensic reports, besides the possibility of quantitative analysis. Due to the great simplicity, the PS(+)-MS technique can also be coupled directly to other separation techniques such as the paper chromatography and can still be used in analyses of LSD blotter, documents and synthetic drugs.
Assuntos
Cocaína/química , Contaminação de Medicamentos , Entorpecentes/química , Benzocaína/análise , Cafeína/análise , Cromatografia em Camada Fina , Humanos , Lidocaína/análise , Espectrometria de Massas/métodos , Fenacetina/análiseRESUMO
Eugenia calycina, which is described as "red pitanga or pitanga cherry of cerrado," is widely distributed in the Cerrado area of Brazil. Its leaf and bark extracts are used in folk medicine for many applications. In this study, the compositions of the major polar compounds of the bark and leaf extracts and their fractions were obtained from a liquid-liquid extraction using hexane, dichloromethane, ethyl acetate, and water. They were then evaluated using electrospray ionization negative FT-ICR mass spectrometry (ESI(-) FT-ICR MS), which revealed a large number of oxygen-containing compounds, such as flavonoids, terpenes, tanins, steroids, and fat acids. The biological activity of these extracts towards several bacterial and fungal strains was then evaluated. The highest activity was found using aqueous fractions, in which the ESI(-) FT-ICR MS analysis revealed compounds with a high content of oxygen (e.g., glycosed flavonoids, tannins, and polyphenolic compounds) against Cryptococcus sp. D (minimum inhibitory concentration [MIC]=15.62µg/mL). Strong activity was also found using the hexanic fractions-in which the ESI(-) FT-ICR MS analysis revealed that the compounds contained a decreased amount of oxygen (e.g., fat acids and steroids)-towards Cryptococcus gatti L48, Cryptococcus neoformans L3 (MIC=31.2µg/mL), and Cryptococcus sp. D (MIC=62.5µg/mL). Therefore, antimicrobial assays using the bark/leaf extracts of E. calycina present prospects for the research of active substances that may be used for the treatment of cryptococcosis, a disease that is common in immunosuppressed patients.