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Maíra Fasciotti Gustavo B. Sanvido Vanessa G. Santos Priscila M. Lalli Michael McCullagh Gilberto F. de Sá Romeu J. Daroda Martin G. Peter Marcos N. Eberlin 《Journal of mass spectrometry : JMS》2012,47(12):1643-1647
The use of CO2 as a massive and polarizable drift gas is shown to greatly improve peak‐to‐peak resolution (Rp‐p), as compared with N2, for the separation of disaccharides in a Synapt G2 traveling wave ion mobility cell. Near or baseline Rp‐p was achieved for three pairs of sodiated molecules of disaccharide isomers, that is, cellobiose and sucrose (Rp‐p = 0.76), maltose and sucrose (Rp‐p = 1.04), and maltose and lactose (Rp‐p = 0.74). Ion mobility mass spectrometry using CO2 as the drift gas offers therefore an attractive alternative for fast and efficient separation of isomeric disaccharides. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Wanderson Romão Marcos F. Franco Gustavo B. Sanvido Fabio C. Gozzo Marcos N. Eberlin 《Polymer Degradation and Stability》2010,95(4):666-2666
Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) has been shown to provide a valuable technique to study the thermomechanical degradation of poly(ethylene terephthalate) (PET). MALDI-MS has been tested to monitor both the admixture of post-consumption bottle-grade PET (PETpc-btg) with virgin bottle-grade PET (PETv-btg) and the thermomechanical degradation effects on the chemical properties of PETv-btg. Principal component analysis of MALDI-MS data classify the samples into groups with specific features: a) PET-btg with intrinsic viscosities of 0.80 or 0.65-0.60 dL g−1); b) processed or virgin PET with the same intrinsic viscosity; c) PETv-btg from PET containing PETpc-btg; and d) PETv-btg from different manufacturers. MALDI-MS data is therefore able to reveal the quality of PET-btg resins preventing frauds and illegal use of recycled PET-btg. 相似文献
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Ambient mass spectrometry: bringing MS into the “real world” 总被引:1,自引:0,他引:1
Rosana M. Alberici Rosineide C. Simas Gustavo B. Sanvido Wanderson Romão Priscila M. Lalli Mario Benassi Ildenize B. S. Cunha Marcos N. Eberlin 《Analytical and bioanalytical chemistry》2010,398(1):265-294
Mass spectrometry has recently undergone a second contemporary revolution with the introduction of a new group of desorption/ionization
(DI) techniques known collectively as ambient mass spectrometry. Performed in an open atmosphere directly on samples in their
natural environments or matrices, or by using auxiliary surfaces, ambient mass spectrometry (MS) has greatly simplified and
increased the speed of MS analysis. Since its debut in 2004 there has been explosive growth in the applications and variants
of ambient MS, and a very comprehensive set of techniques based on different desorption and ionization mechanisms is now available.
Most types of molecules with a large range of masses and polarities can be ionized with great ease and simplicity with the
outstanding combination of the speed, selectivity, and sensitivity of MS detection. This review describes and compares the
basis of ionization and the concepts of the most promising ambient MS techniques known to date and illustrates, via typical
analytical and bioanalytical applications, how ambient MS is helping to bring MS analysis deeper than ever into the “real
world” open atmosphere environment—to wherever MS is needed. 相似文献
4.
Romão W Lalli PM Franco MF Sanvido G Schwab NV Lanaro R Costa JL Sabino BD Bueno MI de Sa GF Daroda RJ de Souza V Eberlin MN 《Analytical and bioanalytical chemistry》2011,400(9):3053-3064
Meta-chlorophenylpiperazine (m-CPP) is a new illicit drug that has been sold as ecstasy tablets. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) and X-ray fluorescence spectrometry (XRF) are shown to provide relatively simple and selective screening tools to distinguish m-CPP tablets from tablets containing amphetamines (mainly 3,4-methylenedioxymethamphetamine (MDMA)). EASI-MS detects the active ingredients in their protonated forms: [m-CPP + H](+) of m/z 197, [MDMA + H](+) of m/z 194, and [2MDMA + HCl + H](+) of m/z 423 and other ions from excipients directly on the tablet surface, providing distinct chemical fingerprints. XRF identifies Cl, K, Ca, Fe, and Cu as inorganic ingredients present in the m-CPP tablets. In contrast, higher Cl concentrations and a more diverse set of elements (P, Cl, Ca, Fe, Cu, Zn, Pt, V, Hf, Ti, Pt, and Zr) were found in MDMA tablets. Principal component analysis applied to XRF data arranged samples in three groups: m-CPP tablets (four samples), MDMA tablets (twenty three samples), and tablets with no active ingredients (three samples). The EASI-MS and XRF techniques were also evaluated to quantify m-CPP in ecstasy tablets, with concentrations ranging from 4 to 40 mg of m-CPP per tablets. The m-CPP could only be differentiated from its isomers (o-CPP and for the three isomers p-CPP) by traveling wave ion mobility mass spectrometry and NMR measurements. 相似文献
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Figueiredo EC Sparrapan R Sanvido GB Santos MG Arruda MA Eberlin MN 《The Analyst》2011,136(18):3753-3757
The association of solid phase extraction with molecularly imprinted polymers (MIP) and electrospray ionization mass spectrometry (ESI-MS) is applied to the direct extraction and quantitation of benzodiazepines in human plasma. The target analytes are sequestered by MIP and directly analyzed by ESI-MS. Due to the MIP highly selective extraction, ionic suppression during ESI is minimized; hence no separation is necessary prior to ESI-MS, which greatly increases analytical speed. Benzodiazepines (medazepam, nitrazepam, diazepam, chlordiazepoxide, clonazepam and midazolam) in human plasma were chosen as a proof-of-principle case of drug analyses by MIP-ESI-MS in a complex matrix. MIP-ESI-MS displayed good figures of merits for medazepam, nitrazepam, diazepam, chlordiazepoxide and midazolam, with analytical calibration curves ranging from 10 to 250 μg L(-1) (r > 0.98) with limit of quantification <10 μg L(-1) and acceptable within-day and between-day precision and accuracy. 相似文献
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Stability analysis in the framework of fluid dynamics is often expressed in terms of a complex eigenvalue problem (EVP). The solution of this EVP describes underlying flow features and their stability characteristics. The main shortcoming of this approach is the high computational cost necessary to solve the EVP, limiting the applicability of this analysis to simple two-dimensional configurations. Many efforts have been focused on overcoming this limitation. Reducing the computational domain to encompass only those regions of physical interest may help alleviate the computational cost. However, the accuracy of the eigenmodes recovered from a reduced region needs to be carefully assessed. In this work, an in-depth analysis of the domain reduction (DR) strategy is presented, and an error estimation tool is provided. The applicability and limitations of this methodology are studied on the open-cavity problem. Next, the error estimation tool is exploited in the transonic buffet phenomenon on a NACA 0012 profile, giving valuable recommendations for the best use of this methodology. Finally, the DR strategy has been applied to investigate the asymmetries induced by jet cooling of turbine blades. 相似文献
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