Abstract: A method of analysing ions provides for separating ions with different charge states. Ions are first thermalized to have substantially the same energy, preferably in an ion trap. Then a barrier height is set to enable ions having a lower charge to escape, while retaining ions with higher charge states. Having effected separation of the ions either or both groups of ions can be subjected to various conventional mass analysis or other processing steps.

Abstract: A MALDI plate construction is provided to support a sample in a manner to effect mass spectrometry of the sample. The plate construction comprises a sample receiving surface, a plate holder for retaining the sample receiving surface and an electrically conductive grid positioned adjacent to the sample receiving surface and in electrical contact with the plate holder.

Abstract: A system and method are described for producing a modifiable fringing field in a multipole instrument, such as a mass spectrometer or an ion guide. The system includes a conductor arrangement having a first pole pair, a second pole pair and an end device for allowing ions to enter or exit the conductor arrangement. A first power supply provides a first voltage to the first pole pair, such that the application of the first voltage results in a fringing field near the end device. An end device power supply provides an end device voltage to the end device for modifying the fringing field to facilitate the entrance or exit of the ions.

Abstract: A method and system for obtaining mass spectrographic data of a substance. The method includes (a) subjecting the substance to a chromatographic process and ionizing the output thereof; (b) obtaining a current mass spectrogram of the output; (c) identifying at least one ion having a fast rising mass signal by comparing the current mass spectrum obtained In step (b) against one or more previously acquired mass spectrums of the output; and (d) fragmenting the identified ion and recording a mass spectrum resulting therefrom.

Abstract: A MALDI plate suitable for MS or MS-MS analysis provided with a composite coating that comprises a hydrophobic coating and a thin layer coating of a mixture of a MALDI matrix material and an intercalating agent such as a polymer is disclosed. A MALDI plate produced in accordance with the present teachings is useful for suppression of matrix ions in the low mass region (<1,000 daltons) of a MALDI-MS spectrum.

Abstract: A method of and apparatus for analyzing a substance takes a stream of ions in said substance and supplies the ions to a collision cell including a quadrupole rod set for guiding the ions and a buffer gas. An RF voltage is applied to the quadrupole rod set to guide ions. An additional alternating current signal is applied to the quadrupole rod set at a frequency selected to cause resonance excitation of the secular frequency of a desired ion, whereby said desired ions are excited and undergo collision with the buffer gas causing fragmentation. The alternating current signal is then modulated, whereby periods in which said alternating current signal is applied alternate with periods in which said alternating signal is not applied.

Abstract: In the field of mass spectrometry, a method of obtaining a mass spectrum enriched with fragment ions while retaining the precursor ion. The technique includes varying the collision energy experienced by the precursor ion such that a range of fragmentations occur. Related methods are also disclosed for obtaining MS, MS2, MS3 and MSn spectra which are enriched with fragment ions.

Abstract: In various aspects, provided are methods for identification of the presence of modified peptides using at least in part mass spectrometric signals from metastable ions that are formed in the field free region of the analyzer. For example, in various embodiments where the modified peptides are phosphopeptides, such metastable ions can appear approximately 95 u lower than the precursor ion m/z value from which they were formed when the peptide contains a phosphate group. In various embodiments, detection of such metastable ions in a MALDI-TOF mass spectrum can identify the modified peptide. In various aspects, provided are methods for identification of the presence of modified peptides using at least in part MS/MS data from two or more of modified peptides, de-modified peptides and non-modified peptides by comparing the sequence and/or site of modification information for two or more of these three forms of a peptide.

Abstract: Sol-gel derived monolithic silica columns containing entrapped dihydrofolate reductase were used for frontal affinity chromatography of small molecule mixtures. The output from the column combined with a second stream containing the matrix molecule (HCCA) and was directly deposited onto a conventional MALDI plate that moved relative to the column via a computer controlled x-y stage, creating a semi-permanent record of the FAC run. The use of MALDI MS allowed for a decoupling of the FAC and MS methods allowing significantly higher ionic strength buffers to be used for FAC studies, which allowed for better retention of protein activity over multiple runs.

Abstract: The present invention relates to glycine transporter inhibiting compounds of formula (I): for treating disorders mediated by GlyT1, wherein R1—R9 are as in the description.

Abstract: This invention comprises an apparatus and method for generating sample ions from sample molecules in which a mixture of a sample and a matrix are vaporized by a laser beam and Subsequently ionized by reagent corona ions. The decoupling of the vaporization and ionization steps allows each process to be separately optimized. The vaporization step can be done in a sub-atmospheric pressure region. Alternatively, the vaporization and ionization steps can be done in a higher pressure region. In addition, the reagent corona ions can be generated in a vacuum chamber or a chamber at atmospheric pressure. Alternatively, the reagent ions can be generated in a sub-atmospheric region while the laser desorption occurs in an atmospheric region.

Abstract: A system and method of analyzing a sample is described. The system includes an ion source and a deflector for producing a plurality of ion beams each of which is detected in distinct detection regions. A detection system uses the information obtained from the detection region to analyze the sample.

Abstract: A process and apparatus are provided for simultaneously moving a first sample plate into an analytical apparatus and a second sample plate from the analytical apparatus. The first sample plate is moved on an entry path which is vertically spaced apart from an exit path for the second sample plate. The transfer mechanism is disclosed in operation with a MALDI-TOF mass spectrometer.

Abstract: A TOF mass analyzer having multiple flight paths is described. The TOF mass analyzer includes a pulsed ion source that generates a packet of ions and that accelerates the packet of ions. An ion deflector directs a first group of ions from the packet of ions to a first ion path, and a second group of ions to a second ion path for each of a first and second predetermined time interval after the pulsed ion source generates the packet of ions. A first TOF mass separator separates the first group of ions according to their mass to-charge ratio and a first detector is positioned to receive the first group of ions A second TOF mass separator separates a second group of ions according to their mass to-charge ratio and a second detector is positioned to receive the second group of ions. Additional ion paths may be employed, and any type of TOF mass separator may be used in each ion path.

Abstract: A mass spectrometry quantitation technique enables high-throughput quantitation of small molecules using a laser-desorption (e.g., MALDI) ion source coupled to a triple-quadrupole mass analyzer. The ions generated from the ion source are collisionally damped/cooled, and then quantitatively analyzed using the triple-quadrupole analyzer operated in the multiple-reaction-monitoring (MRM) mode. Significantly improved measurement sensitivity is obtained by applying laser pulses to the ion source at a high pulse rate of about 500 Hz or higher. This allows the data acquisition to be performed rapidly, and the speed of about one second for each sample point on the ion source target has been achieved.

Abstract: The invention solves the problem of artifact ghost peaks which can sometimes arise in mass spectrometers that employ a quadrupole rod set for both trapping and mass analyzing the trapped ions. The problem arises as a result of randomly distributed voltage gradients along the length of the rods. Three solutions are presented. The first approach involves improving the conduction characteristics of the rod sets. The second approach involves the application of at least one continuous axial DC field to the trapping quadrupole rod set in order to urge ions towards a pre-determined region of the trap, thereby avoiding voltage gradients. The third approach involves the application of one or more discrete axial fields to create one or more potential barriers along the axial dimension of the trap (in addition to the barriers used to initially trap the ions). These barriers prevent ions of differing voltage gradients from equilibrating with one another.

Abstract: A sample plate for a MALDI process is provided which comprises an electrically conductive substrate having a hydrophobic coating whose thickness and hydrophobic character can be modified by changing the coating substrate and/or the concentration of the substrate. Different coating substances that have provided optimal performance of the sample plate for reproducible deposition and analysis by MALDI-MS and MALDI-MS/MS processes of analyte mixtures include synthetic waxes such as paraffin compositions, lipids, organic acids, silicon-containing compounds, silica polymers and natural waxes. Metal polishes that have been used to clean and regenerate plate surfaces have also provided a sample plate that has optimal performance for reproducible deposition and analysis by MALDI-MS and MALDI-MS/MS processes of analyte mixtures.

Abstract: A method of detecting and measuring phosphorus in samples is disclosed. The measurement of phosphorylation is made with an inductively coupled plasma mass spectrometer (ICP-MS), coupled to a reactive collision cell. The reactive collision cell is employed to ensure interference-free detection of phosphorus ions, by the formation of product ions with a different mass to charge ratio. Accurate measurement of phosphorylation in samples is important in proteomics.

Abstract: Collisional cooling of ions in mass spectrometry has been known for sometime. It is known that collisional cooling can promote focusing of ions along the axis of an ion guide. A similar technique has been used to enhance coupling of a pulsed ion source such as a MALDI source to a Time of Flight instrument. It is now realized that it is desirable to provide, immediately adjacent to a MALDI or other ion source, a low-pressure region to promote ionization conditions most favorable for the particular ion source. Then, with the ions released and free, the ions are subjected to relatively rapid collisional cooling in a high pressure region adjacent to the ionization region. This will dissipate excess of internal energy in the ions, so as to substantially reduce the incidence of metastable fragmentation of the ions. The ions can then be subjected to conventional mass analysis steps.

Abstract: A sample introduction device for introducing a plurality of independent fluid sample streams into a mass spectrometer includes a manifold (84) having a plurality of fluid sample stream direct paths. Each direct path extends between a fluid sample stream inlet (80, 82) and a fluid sample stream outlet. A plurality of bypass paths (92, 96) is also provided in the manifold. Each bypass path is coupled to a respective one of the direct paths between the inlet and outlet. A plurality of transfer lines (86, 94) is also provided with each transfer line being coupled to a respective one of the outlets to deliver a fluid sample stream to an ionization region of the mass spectrometer. A valve (90, 96) is positioned in each of the bypass paths and is actuable to divert the fluid sample stream entering the direct path via the inlet from the direct path and into the bypass path.