The first chalcone-based colorimetric chemosensor DPP (sodium (E)-2,4-dichloro-6-(3-oxo-3-(pyridine-2-yl)prop-1-en-1-yl)phenolate) was synthesized for detecting Ni2+ in near-perfect water. synthesis of validated by using 1H, 13C NMR and ESI-MS. selectively sensed through the color variation from yellow to purple. Detection limit calculated be 0.36 μM (3σ/slope), which is below standard (1.2 μM)...

The purpose of the work presented here was to evaluate the influence of solution composition and analyte characteristics on responsiveness to analysis with negative ion electrospray ionization mass spectrometry. The responses of a series of structurally diverse acidic molecules were compared in various solvents. Response was generally observed to be higher in methanol than acetonitrile and resp...

Conventionally, electrospray ionization ion trap mass spectrometry (ESI-ITMS) is not used for the analysis of metal ions because metal ions may be of too low mass to be trapped by the mass analyzer. Furthermore, metal ions can easily precipitate during ESI processes because of their poor volatilities. We present an approach for solving these two problems using milk as the sample to demonstrate ...

Electrical source imaging (ESI) aims at reconstructing the electrical brain activity from scalp EEG. When applied to interictal epileptiform discharges (IEDs), this technique is of great use for identifying the irritative zone in focal epilepsies. Inaccuracies in the modeling of electro-magnetic field propagation in the head (forward model) may strongly influence ESI and lead to mislocalization...

A set of signal processing methods comprising fast Fourier transform interpolation, maximum entropy deconvolution and wavelet transformation has been successfully integrated to improve the equality of the extracted C K-edge spectra from electron spectroscopic imaging (ESI) series. Fast Fourier transform interpolation is used to improve the dispersion arising from discrete sampling of ESI series...

The applicability of high-resolution electrospray ionization mass spectrometry (HR ESI-MS) to measurements of the average oxygen to carbon ratio (O/C) in secondary organic aerosols (SOAs) was investigated. Solutions with known average O/C containing up to 10 standard compounds representative of low-molecular-weight SOA constituents were analyzed and the corresponding electrospray ionization eff...

The increasing amounts of electronically stored information (esi) relevant to civil litigation, and the ease their loss, caused federal lawmakers explicitly address possible consequences certain presuit or postsuit esi losses. These acted in both 2006 2015 through Federal Civil Procedure (FRCP) 37(e). But they only on esi. Their actions have prompted attention significant risks losses all esi, ...

Complex extracts of rosemary honey constituents often require very effective separation techniques to allow the identification of different compounds. Capillary electrophoresis (CE) coupled to mass spectrometry (MS) detection can provide structure-selective information about the analytes in such matrices and has turned out to be an attractive alternative to HPLC methods. A simple and cost-effec...

This paper demonstrates the applicability of electron-spectroscopic imaging (ESI) for valence-state mapping of the iron oxide system. We have previously developed a set of signal-processing methods for an ESI series, to allow mapping of sp(2)/sp(3) ratio, dielectric function and energy bandgap. In this study, these methods are applied to generate a valence-state map of an iron oxide thin film (...

The thermal stability of ribonuclease S (RNase S), an enzymatically active noncovalent complex composed of a 2166-u peptide (S-peptide) and a 11,534-u protein (S-protein), was investigated by electrospray ionization mass spectrometry (ESI-MS) and capillary electrophoresis ESI-MS (CE-ESI-MS). The intensities of peaks corresponding to the RNase S complex were inversely related to both the applied...