For rhodamine B, tandem MS capability is also demonstrated.
Although QqTOF platforms have both tandem MS capability and superior mass accuracy, it suffers from decreased sensitivity and a limited data acquisition range (up to 4 kDa), compared to the SELDI-TOF MS platform (up to 200 kDa).
This instrument is a modified version of the QSTAR XL (AB SCIEX, Framingham, MA) featuring a 20 kV DC C60 primary ion beam for SIMS, a translational sample stage that enables imaging experiments, tandem MS (MS/MS) capability via collision induced dissociation (CID), and high mass resolution (R > 10 000).
A benchtop miniature mass spectrometer system, Mini 12, with ambient ionization source and tandem mass spectrometry capabilities has been developed and characterized.
The strategy targets the two-ion-gun approach to maximize ionization with reduced damage, laser postionization to maximize ionization efficiency, and the implementation of an orbitrap device for ultrahigh mass resolution with tandem mass spectrometry capabilities.
However, technologies to increase the capability of tandem mass spectrometry proteomics to identify and quantify candidates are rapidly evolving and other technologies such as antibody arrays and fluorescent bead assays are also potential platforms for clinical implementations.
Recent developments in instrument design have led to lower limits of detection, while new ion activation techniques and improved understanding of gas-phase ion chemistry have enhanced the capabilities of tandem mass spectrometry for peptide and protein structure elucidation.
A general characteristic of recent mass spectrometers is that most are composed of a sequence of multiple mass analyzers with different strengths and properties, resulting in tandem instruments that possess capabilities unattainable by the individual components (Fig. 1A).
Tandem quadrapole mass spectrometric capabilities and high resolution permits the determination of amino acid sequence of peptides.
It was found that extension of the suspension wire between the payload and the super-pressure balloon can extend the capability of the tandem system; the altitude of the zero-pressure balloon can be changed without any consumables except some energy, and the day night oscillation of the balloon altitude can be suppressed.
