Abstract: A method of enhanced speciation of both positive and negatives species in an analyte is disclosed. The method can include producing a first analyte solution comprising an analyte composition and an effective amount of silver triflate, and analyzing the first analyte solution with an electrospray ionization mass spectrometer. The method can also include producing a second analyte solution comprising a portion of the analyte composition and an effective amount of a compound of formula I, and analyzing the second analyte solution with an electrospray ionization mass spectrometer. The compound of formula I is [NX+][OH?], where X is a linear, branched, or cyclic C1-C10 alkane; an aryl; a heterocyclic aromatic; or a heterocyclic moiety.

Abstract: A method of enhanced speciation of both positive and negatives species in an analyte is disclosed. The method can include producing a first analyte solution comprising an analyte composition and an effective amount of silver triflate, and analyzing the first analyte solution with an electrospray ionization mass spectrometer. The method can also include producing a second analyte solution comprising a portion of the analyte composition and an effective amount of a compound of formula I, and analyzing the second analyte solution with an electrospray ionization mass spectrometer. The compound of formula I is [NX+][OH?], where X is a linear, branched, or cyclic C1-C10 alkane; an aryl; a heterocyclic aromatic; or a heterocyclic moiety.

Abstract: A method of enhanced speciation of both positive and negatives species in an analyte is disclosed. The method can include producing a first analyte solution comprising an analyte composition and an effective amount of silver triflate, and analyzing the first analyte solution with an electrospray ionization mass spectrometer. The method can also include producing a second analyte solution comprising a portion of the analyte composition and an effective amount of a compound of formula I, and analyzing the second analyte solution with an electrospray ionization mass spectrometer. The compound of formula I is [NX+][OH?], where X is a linear, branched, or cyclic C1-C10 alkane; an aryl; a heterocyclic aromatic; or a heterocyclic moiety.

Abstract: A method for quantifying the presence of naphthenic acids in a hydrocarbon-comprising liquid that includes: contacting a hydrocarbon-comprising liquid with gaseous ammonia; isolating a reaction product produced by the contacting step; and analyzing the reaction product for the presence of naphthenates using a mass spectrometry technique. The naphthenic acids known to form commercial naphthenate deposits can be (i) ions of tetraprotic carboxylic acids having molecular weights ranging from 1225 to 1270 Daltons, (ii) n-alkyl or branched carboxylic acids having molecular weights ranging from 250 to 650 Daltons, or (iii) both.

Abstract: Analytical methods using hydrogen/deuterium exchange are provided which reduce or eliminate the back-exchange of deuterium for hydrogen. The methods, which are useful in protein and peptide mapping, include the steps of (a) providing a peptide or protein comprising a solvent accessible hydrogen; (b) exchanging the solvent accessible hydrogen for a deuterium; (c) separating the peptide or protein with supercritical fluid chromatography; and (d) analyzing by mass spectrometry the mass of the separated peptide or protein. Supercritical fluid chromatography enables the observation of fast exchanging hydrogen atoms missed using conventional liquid chromatography methods.

Abstract: A method of enhanced speciation of both positive and negatives species in an analyte is disclosed. The method can include producing a first analyte solution comprising an analyte composition and an effective amount of silver triflate, and analyzing the first analyte solution with an electrospray ionization mass spectrometer. The method can also include producing a second analyte solution comprising a portion of the analyte composition and an effective amount of a compound of formula I, and analyzing the second analyte solution with an electrospray ionization mass spectrometer. The compound of formula I is [NX+][OH?], where X is a linear, branched, or cyclic C1-C10 alkane; an aryl; a heterocyclic aromatic; or a heterocyclic moiety.

Abstract: A method for quantifying the presence of naphthenic acids in a hydrocarbon-comprising liquid that includes: contacting a hydrocarbon-comprising liquid with gaseous ammonia; isolating a reaction product produced by the contacting step; and analyzing the reaction product for the presence of naphthenates using a mass spectrometry technique. The naphthenic acids known to form commercial naphthenate deposits can be (i) ions of tetraprotic carboxylic acids having molecular weights ranging from 1225 to 1270 Daltons, (ii) n-alkyl or branched carboxylic acids having molecular weights ranging from 250 to 650 Daltons, or (iii) both.

Abstract: A method is provided for quantifying endogenous sphingolipids in a biological system. The method includes preparing one or more isotope labeled amino acids; introducing the isotope labeled amino acids into a biological system; extracting and separating a sphingolipid-containing fraction from the biological system; and quantifying the amount of endogenous sphingolipids in the biological system. The isotope-labeled amino acid may include a non-essential amino acid, and the method may further include adding an amino acid synthesis inhibitor into the biological system. Systems and kits for quantifying endogenous sphingolipids also are disclosed.

Abstract: Analytical methods using hydrogen/deuterium exchange are provided which reduce or eliminate the back-exchange of deuterium for hydrogen. The methods, which are useful in protein and peptide mapping, include the steps of (a) providing a peptide or protein comprising a solvent accessible hydrogen; (b) exchanging the solvent accessible hydrogen for a deuterium; (c) separating the peptide or protein with supercritical fluid chromatography; and (d) analyzing by mass spectrometry the mass of the separated peptide or protein. Supercritical fluid chromatography enables the observation of fast exchanging hydrogen atoms missed using conventional liquid chromatography methods.

Abstract: Analytical methods using hydrogen/deuterium exchange are provided which reduce or eliminate the back-exchange of deuterium for hydrogen. The methods, which are useful in protein and peptide mapping, include the steps of (a) providing a peptide or protein comprising a solvent accessible hydrogen; (b) exchanging the solvent accessible hydrogen for a deuterium; (c) separating the peptide or protein with supercritical fluid chromatography; and (d) analyzing by mass spectrometry the mass of the separated peptide or protein. Supercritical fluid chromatography enables the observation of fast exchanging hydrogen atoms missed using conventional liquid chromatography methods.

Abstract: A high resolution Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry system includes excitation circuitry including an excitation amplifier for generating an electrical excitation signal and excitation electrodes for applying an oscillating electric field to excite ions in the system. Detection circuitry including detection electrodes measures a detection signal which includes a plurality of signal values including signal values induced by the ions. Structure is provided for reducing or canceling coupling of the excitation signal into the detection signal, wherein simultaneous excitation and detection is used. A computing structure generates a Fourier transformed frequency domain representation of the detection signal and deconvolves the frequency domain representation using complex division to separate a dispersion spectrum portion and an absorption spectrum portion.

Abstract: A rotary air preheater has a rotor, at least one seal disposed proximate to the rotor, a drive for reciprocally driving a portion of the seal between a first position adjacent the rotor and a second position spaced from the first position, and a control system for activating the drive. The control system includes a boiler load power sensor, means for storing a first stored boiler load having a value between the minimum boiler load and the maximum boiler load, and logic for comparing the sensed boiler load to the first stored boiler load. The logic provides a first activation signal to the drive when the sensed boiler load rises above the first stored boiler load and a second activation signal to the drive when the sensed boiler load falls below the first stored boiler load. The first activation signal activates the drive to drive the portion of the seal to the first position and the second activation signal activates the drive to drive the portion of the seal to the second position.

Abstract: An ion cyclotron resonance cell (20) in which samples are analyzed has plates (21, 22) serving as excitation electrodes, top and bottom plates (25, 26) serving as detector electrodes and end trapping plates (23, 24). The cell (20) is maintained in a magnetic field of flux density B oriented longitudinally between the end trapping plates (23, 24). An ion generating source (30) causes ionization of the sample molecules within the cell (20). An electrostatic trapping potential is applied to the end trapping plates (23, 24) to prevent ions from escaping in the direction of the magnetic field B. Grounded screens (40, 41) are positioned within the cell (20) just inside the end trapping plates (23, 24) to reduce an electrostatic electric field in the cell (20) resulting from the application of a potential to the end trapping plates (23, 24).

Abstract: An ion cyclotron resonance cell has applied thereto an excitation which has a time domain waveform which is the inverse Fourier transform of a frequency domain excitation spectrum which has been chosen by the user to yield selective excitation and/or suppression of ranges of ion mass-to-charge ratios. To minimize the dynamic range of the time domain signal resulting from the inverse Fourier transform, the phases of the various discrete frequency components in the frequency domain spectrum which are used in calculating the inverse Fourier transform are not constant but rather are varied as a function of the frequency of the components. The phase of each component is assigned such that the frequency components in the time domain signal are not all in phase at any point in time, thereby avoiding large magnitude spikes in the time domain waveform. The phases of the various frequency components may follow a non-linear function of the frequencies of the components, such as a quadratic function.