Fast Analysis of Taurine in Energetic Drinks by Electrospray Ionization Mass Spectrometry

Santos, LS (Santos, Leonardo S.). Univ Talca, Inst Quim Recursos Nat, Lab Asymmetr Synth, Talca, ChileDirect infusion electrospray ionization tandem mass spectrometry in the negative ion mode with single reaction monitoring is show to allow high selectivity and sensitivity in the quantification of taurine in energetic drinks. The method is also simple and rapid (less than 2 min run time), with high recovery and repeatability. Commercially available energetic drinks were found to contain taurine in concentrations quite different (lower or higher) from the declared amounts

Trace level analysis of VOCs and semi-VOCs in aqueous solution using a direct insertion membrane probe and trap and release membrane introduction mass spectrometry

A new design for a trap and release membrane introduction mass spectrometry (T&R-MIMS) system using a removable direct insertion membrane probe (DIMP) for combined trace level analysis (low or sub ppb range) of volatile (VOC) and semi-volatile organic compounds (SVOCs) is reported. The system differs from the original T&R-MIMS system (M. Leth and F. R. Lauritsen, Rapid Commun. Mass Spectrom., 1995, 9, 591) as it uses a removable DIMP probe to place a capillary membrane loop inside the ion source block exactly between two parallel filaments. The more versatile DIMP-T&R-MIMS system can be operated, during the trapping step of T&R-MIMS analysis, in the standard MIMS mode for VOC detection; during the T&R-MIMS thermal desorption step needed for SVOC analysis, the system permits faster and more uniform heating of the membrane, thus SVOC sensitivity is improved and memory effects are minimized.1251212

Natural and artificial markers of gasoline detected by membrane introduction mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A few hydrocarbons in gasoline display relatively high solubility in water and may function therefore as its characteristic set of natural markers. These markers are detected from an aqueous gasoline extract via membrane introduction mass spectrometry (MIMS) producing characteristic chemical profiles. MIMS adds a second selectivity criterion detecting only the water soluble hydrocarbons that most easily permeate through a silicone membrane. MIMS screening and the use of artificial markers for gasoline with similar chemical properties (high water solubility and membrane permeability) as those of its natural markers is proposed. MIMS provides a reliable screening method for natural and artificial markers in gasoline for its typification and to monitor adulteration and origin.33751754Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Financing Agency for Studies and Projects (FINEP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Evaluation of metal-ion stress in sunflower (Helianthus annuus L.) leaves through proteomic changes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)In this work, sunflowers (Helianthus annuus L.) were cultivated using soil and vermicompost as substrate, and plant irrigation was carried out using either a Zn solution or a mixed ions solution (Cd, Cu, Pb and Zn). After plant harvesting, the effects of metal-ion contamination on proteins expression (either up- or down-regulation) in sunflower leaves were evaluated using two-dimensional electrophoresis (2-DE), gel images and mass spectrometry (MALDI-QTOF MS). When Zn or mixed ions solution was added to the substrate, nine proteins showed different expressions. Another twenty-three protein spots also showed considerable variation when both treatments (Zn or mixed ions) were applied. Twelve of these proteins were successfully characterized, six of them being reported for the first time in Helianthus annuus L. Two other proteins showed new sequences that have been downloaded to the protein databank.11107113Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Financiadora de Estudos e Projetos (FINEP)Proteomic Network of the Sao PauloFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Comparative metallomics for transgenic and non-transgenic soybeans

In this work, a comparative metallomics of transgenic and non- transgenic soybeans [ Glycine max ( L.) Merrill] was performed. Soybean proteins were extracted with a proper buffer and separated by two- dimensional polyacrylamide gel electrophoresis. Metal ions bound to a set of eight proteins randomly selected ( ranging from 13.98 to 54.87 kDa), were characterized by matrixassisted laser desorption- ionization quadrupole- time of flight mass spectrometry and mapped using synchrotron radiation X- ray spectrometry. The metal ions detected were: Ca( II), Cu( II), Fe( II), Mn( II), Ni( II) and Zn( II). Transgenic and non- transgenic soybeans proteins were found to display typical and random profiles for metal ions binding. To test the reliability of the qualitative metal ions profiles, quantification of Ca( II), Cu( II) and Fe( II) was performed via microwave-assisted decomposition in mini- vials followed by atomic absorption spectrometry determination. Qualitative and quantitative metallomics was found to be coherent and to match profiles expected from the known protein functions. The protein of spot 5, with molar mass of 37.62 kDa ( amino acid sequence presented), was found to display the most characteristic change in metal ions content, with higher Ca( II), Cu( II) and Fe( II) concentrations for transgenic soybeans.22121501150

A new method for the selective quantitation of cyanogenic glycosides by membrane introduction mass spectrometry

A new method is described for the rapid, sensitive, virtually interference-free, and selective quantitation of cyanogenic glycosides in aqueous extracts using membrane introduction mass spectrometry (MIMS). Selective monitoring, by either conventional MIMS or cryotrap-MIMS, not of HCN but of the co-released ketones (acetone and butan-2-one), when performed for both the crude cassava extracts and the linamarase-NaOH-hydrolyzed extracts, is found to offer an advantageous alternative to classic spectrophotometric methods based on HCN analysis for the selective quantitation of the two cyanogenic glycosides linamarin and lotaustralin expressed as both the free HCN content and the total cyanogenic potential (total HCN).12591529153

Determination of phthalates in water using fiber introduction mass spectrometry

Fiber introduction mass spectrometry (FIMS) - a direct coupling of SPME and MS - using selective ion monitoring (SIM) was used to detect and quantify dimethylphthalate (DMP), diethylphthalate (DEP) and dipropylphthalate (DPP) in mineral water. In FIMS, a chromatographic silicone septum is the only barrier between ambient and the high-vacuum mass spectrometer, permitting direct introduction of the SPME fiber into the ionization region of the equipment. After their thermal desorption and ionization and dissociation, the extracted phthalates are detected and quantitated by MS. Three types of SPME fibers were screened for best analyte sorption/desorption behaviors: 100 mum polydimethylsiloxane ( PDMS), 65 mum polydimethylsiloxane/divinylbenzene (PDMS/DVB) and 65 mum Carbowax/divinylbenzene (CW/DVB). The PDMS/DVB and CW/DVB fibers were then evaluated for precision, and quantitative figures of merit were assessed for extractions using the PDMS/DVB fiber, which displayed the best overall performance. FIMS with the PDMS/DVB fiber allows simple extraction and MS detection and quantitation of DMP in water with good linearity and precision, and at concentrations as low as 3.6 mug L-1. The LD and LQ of FIMS are below the maximum phthalate concentration allowed by the USEPA for drinking water ( 6 mug L-1).130218819

Solid phase micro-extraction in a miniature ion trap mass spectrometer

Fiber introduction mass spectrometry (FIMS), a variation of solid-phase microextraction (SPME) and membrane introduction mass spectrometry (MIMS), is employed with a miniature mass spectrometer. The inlet system, constructed of commercially available vacuum parts, allows the direct introduction of the SPME needle vacuum chamber into the mass spectrometer. Thermal desorption of the analyte from the poly(dimethylsiloxane) (PDMS) coated fiber was achieved with a built in nichrome heater, followed by electron ionization of the analytes internal to the cylindrical ion trap (CIT). The system has been tested with several volatile organic compounds (VOC) in air and to analyze the headspace over aqueous solutions, with limits of detection in the low ppb range. The signal rise (10-90%) and fall (90-10%) times for the system ranged from 0.1 to 1 s (rise) and 1.2 to 6 s (fall) using heated desorption. In addition, this method has been applied to quantitation of toluene in benzene, toluene, xylene (BTX) mixtures in water and gasoline. This simple and rapid analysis method, coupled to a portable mass spectrometer, has been shown to provide a robust, simple, rapid, reproducible, accurate and sensitive (low ppb range) fieldable approach to the effective in situ analysis of VOC in various matrices.12891119112

Quantitation of drugs via molecularly imprinted polymer solid phase extraction and electrospray ionization mass spectrometry: benzodiazepines in human plasma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)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 mu g L(-1) (r > 0.98) with limit of quantification <10 mu g L(-1) and acceptable within-day and between-day precision and accuracy.1361837533757Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Ministerio de Ciencia e Tecnologia (INOMAT)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG, Belo Horizonte, Brazil) [CDS-APQ-01323-09, CDS-APQ-01612-10

Organoindate room temperature ionic liquid: Synthesis, physicochemical properties and application

The combination of equimolar amounts of solid 1-n-butyl-3-methylimidazolum chloride (BMI-Cl) with solid indium trichloride affords the new room temperature and air stable ionic liquid BMI.InCl4 (mp -6 degreesC). The major physicochemical properties (density, viscosity, electrical conductivity and electrochemical window) of BMI.InCl4 are complementary to those of classical tetrafluoroborate or hexafluorophosphate analogues. However, this liquid possesses similar Lewis acidity properties to those of organoaluminate melts and can be used as recyclable media, as demonstrated here for the tetrahydropyranylation of alcohols.81155115