An ion-mobility spectrometer system includes a housing with an upstream end, a downstream end, and a drift region defined along a longitudinal axis through the housing between the upstream and downstream ends. A first ionizer is operatively connected the housing to supply ions at the upstream end. A second ionizer is operatively connected to the housing to supply ions at the upstream end, wherein the first and second ionizers are both situated upstream of the drift zone relative to an ion flow path through the drift zone. An electric field generator is operatively connected to the housing to drive ions through the drift zone in a direction from the upstream end toward the downstream end. The second ionizer is a radioactive ionizer mounted to the housing at the upstream end positioned to direct irradiated ions into the housing.

A dissociation device fragments a precursor ion, producing at least two different product ions with overlapping m/z values in the dissociation device. The dissociation device applies an AC voltage and a DC voltage creating a pseudopotential that traps ions below a threshold m/z including the at least two product ions. The dissociation device receives a charge reducing reagent that causes the trapped at least two product ions to be charge reduced until their m/z values increase above the threshold m/z set by the AC voltage. The increase in the m/z values of the at least two product ions decreases their overlap. The at least two product ions with increased m/z values are transmitted to another device for subsequent mass analysis by applying the DC voltage to the dissociation device relative to a DC voltage applied to the other device.

The present invention provides a method for specifically cleaving a Cα-C bond of a peptide backbone and/or a side chain of a protein and a peptide, and a method for determining amino acid sequences of protein and peptide. A method for specifically cleaving a Cα-C bond of a peptide backbone and/or a side chain bond of a protein or a peptide, comprising irradiating a protein or a peptide with laser light in the presence of at least one hydroxynitrobenzoic acid selected from the group consisting of 3-hydroxy-2-nitrobenzoic acid, 4-hydroxy-3-nitrobenzoic acid, 5-hydroxy-2-nitrobenzoic acid, 3-hydroxy-5-nitrobenzoic acid, and 4-hydroxy-2-nitrobenzoic acid. A method for determining an amino acid sequence of a protein or a peptide, comprising irradiating a protein or a peptide with laser light in the presence of the above specific hydroxynitrobenzoic acid to specifically cleave a Cα-C bond of a peptide backbone and/or a side chain bond, and analyzing generated fragment ions by mass spectrometry.

The invention relates to a tandem mass spectrometer comprising an ionization source that can produce ions; a mass analyzer comprising an ion trap arranged in such a way as to receive ions from the ion source and a detector that can detect ions leaving the ion trap according to the mass to charge (m/z) ratio thereof; ion activation means for activating ions that can fragment at least some of the ions trapped in the ion trap; and coupling means arranged between the ion trap and said ion activation means. According to the invention, the ion activation means consists of a glow discharge lamp that can generate a light beam oriented towards the ion trap, said light beam being electromagnetic radiation in the vacuum ultraviolet wavelength range with photon energies of between 8 eV and 41 eV in such a way as to fragment at least some of the ions trapped in the ion trap.

A method of analyzing molecules, comprising: generating ions from a sample of molecules; cooling the generated ions below ambient temperature; fragmenting at least some of the cooled ions by irradiating the ions with light at a plurality of different wavelengths (λ) within one or more predetermined spectral intervals; recording a fragment mass spectrum of the fragmented ions comprising a detected signal (I) versus m/z over a predetermined range of m/z values for each of the plurality of different wavelengths (λ), thereby recording a two dimensional dependency of the detected signal (I) on m/z and irradiation wavelength (λ); and determining from the recorded two dimensional dependency an identity of at least one of the generated ions and/or relative abundances of different generated ions and thereby determining an identity of at least of one of the molecules and/or relative abundances of different molecules in the sample.

A dissociation device fragments a precursor ion, producing at least two different product ions with overlapping m/z values in the dissociation device. The dissociation device applies an AC voltage and a DC voltage creating a pseudopotential that traps ions below a threshold m/z including the at least two product ions. The dissociation device receives a charge reducing reagent that causes the trapped at least two product ions to be charge reduced until their m/z values increase above the threshold m/z set by the AC voltage. The increase in the m/z values of the at least two product ions decreases their overlap. The at least two product ions with increased m/z values are transmitted to another device for subsequent mass analysis by applying the DC voltage to the dissociation device relative to a DC voltage applied to the other device.

A dissociation device fragments a precursor ion, producing at least two different product ions with overlapping m/z values in the dissociation device. The dissociation device applies an AC voltage and a DC voltage creating a pseudopotential that traps ions below a threshold m/z including the at least two product ions. The dissociation device receives a charge reducing reagent that causes the trapped at least two product ions to be charge reduced until their m/z values increase above the threshold m/z set by the AC voltage. The increase in the m/z values of the at least two product ions decreases their overlap. The at least two product ions with increased m/z values are transmitted to another device for subsequent mass analysis by applying the DC voltage to the dissociation device relative to a DC voltage applied to the other device.

Methods are described for using a combination of mass spectroscopic and proteomic approaches for identifying the specific pairing of heavy and light chains for an intact antibody, an antibody fragment, a mixture of intact antibodies, or a mixture of antibody fragments.

An ambient or atmospheric pressure ion source is disclosed that comprises a laser source (1) that generates ions and/or neutral particles from a target (2). A transfer device (10) causes the ions and/or neutral particles to pass along a first path or axis within the transfer device (10), while a secondary activation device (6) directs laser radiation or photons along, across or over at least a portion of the first path or axis to cause secondary activation of the ions and/or neutral particles.

Systems, methods, and devices to dissociate ions using one or more light emitting diodes (LEDs). A mass spectrometer for ion dissociation includes an ion source for providing ions for dissociation, a mass analyzer, and a photodissociation (PD) device. The PD device includes an ion transport device. The ion transport device is configured perform one or more of: transporting the ions through the PD device, and trapping the ions within a region of the PD device. The PD device also includes one or more LEDs positioned to irradiate the ions in the PD device, resulting in fragmentation of the ions.