Triple-stage quadrupole mass spectrometer

In general, triple stage quadrupole mass spectrometer with ESI in positive ion mode is perceived as the most appropriate MS technique available at present for small—mostly basic—molecules and was used for the assay of nilotinib [112], sorafenib [115,116], lapatinib [117], sunitinib [113,114], bosutinib [88], vatalanib [119] axitinib [120], vandetanib [118] neratinib [87], and crizotinib [125], The latter assay for crizotinib was developed for preclinical experiments and does not contain... 

Figure 7. Triple-stage quadrupole mass spectrometer in operation.

FIGURE 4.5 The five mass spectrometers commonly used for proteomic research, (a) ESI triple-stage quadrupole mass spectrometer (b) ESI quadrupole ion trap (QIT) mass spectrometer (c) MALDI time-of-flight mass spectrometer. 

Figure 1.9. Triple-stage quadrupole Quantum mass spectrometer capable of operating under enhanced resolution conditions. To reduce the chemical noise and to improve the sensitivity, the mass analyzers were oriented in an L shape rather than the conventional straight design. An additional benefit of the L shape orientation is a smaller foot print. (Courtesy of ThermoFisher Scientific.)...

Figure 1.14. MRM chromatograms of SCH 29851 (383.0. 337.0) and SCH 34117 (311.1 259.1) obtained using Sciex API 3000 (triple-stage quadrupole) and Sciex QSTAR pulsar (Q-TOF). Comparison of MRM chromatograms of SCH 29851 and SCH 34117 obtained at the LOQ (1 ng/mL) using the API 3000 mass spectrometer with those from the Q-TOF mass spectrometer indicated that the S/N ratio is at least 10-20 times better on the API 3000 mass spectrometer. However, the MRM chromatograms from the API 3000 mass spectrometer do not provide the option to further examine the MS/MS spectra whereas the full-scan MS/MS spectra from a Q-TOF based quantitative bioanalysis assay allows one to easily eliminate any questions about false-positive data. (Rephnted with permission from Yang et a ., 2001b.)...

Detection of imatinib is performed by triple quadrupole mass spectrometer with an electrospray ionization (ESI) interface operated in positive ion mode [103, 104, 106,107,109,110]. Except the methods published by Parise et al. for imatinib and its main metabolite [108], and for nilotinib [111], where a single quadrupole mass spectrometer was used, most TKIs are analyzed in plasma by atmospheric pressure ionization (electrospray or turbo ion spray) coupled to triple stage mass spectrometer. Expectedly, higher limit of quantifications for imatinib (30 ng/ml) [108], and nilotinib (5 ng/ml) [111], are obtained for the assays using single quadrupole MS (see Table 2). 

Among these, both LC-MS and LC-MS/MS approaches have been described using different mass analyzers operating in the positive ion mode scan such as triple stage quadrupole (TSQ) mass spectrometers [145, 194, 226, 227, 235, 239, 240, 242-247] and hybrid quadrupole-linear ion trap (LTQ) [173, 193, 218, 238, 241] mass spectrometers working in SRM mode as well as time-of-flight (TOF) [195] and hybrid quadrupole-TOF (Q-TOF) [236,237] mass spectrometers working in the MS mode. 

A second type of MS instrument capable of performing a product ion scanning experiment is the ion trap mass spectrometer. The difference between this instrument and the triple quadrupole mass spectrometer is the ion trap is capable of performing numerous sequential product ion experiments on the same compound. For example, a potential metabolite is dissociated into several characteristic fragment ions in the first stage of MS/MS. Then, one of these fragment ions can be further dissociated into smaller ions. This is a second stage of MS/MS known as MS. This process can continue until the site of meta-... 

Note The triple-quadrupole mass spectrometer can be configured for single-stage operation. 

Another LDI instrument that was similar in principle to LAMMA was developed by Perchalski (1985) that featured the additional selectivity of two stages of mass analysis provided by a triple quadrupole mass spectrometer (QqQ). The LDI QqQ was shown to have potential for use as a probe-type analyzer for molecular analysis of mixtures, as demonstrated by the detection of a mixture of nine antiepileptic drugs by monitoring the precursor ion/product ion pair for each drug (Perchalski et al., 1983). The LDI—QqQ, however, was determined to be too slow to adequately characterize molecules ionized by cationization or anionization after desorption by a single-shot laser. Also, the vaporization/ionization process on the LDI—QqQ was unable to ionize polar, nonvolatile, and/or thermally unstable molecules (Perchalski, 1985). 

Because of the advances in the gas-phase ionization of biomacromolecules, such as electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI), mass spectrometry (MS) has become a powerful tool for detection, identification, and structural analysis of proteins, peptides, and polynucleotides. The molecules ionized in a gas phase by these methods are subsequently analyzed by sector, quadrupole, ion-trap, or time-of-flight mass spectrometers. In particular, the MS systems consisting of ESI and triple-stage quadrupole (ESI/TSQ) or ion-trap (IT) mass spectrometry and MALDI time-of-flight (MALDl/TOF) mass spectrometry have been most widely applied to the field of protein chemistry for the accurate determination of molecular mass of proteins and peptides, determination of amino acid sequence, identification of proteins by peptide mass databases, and analysis of posttranslational modifications such as phosphorylation and glycosylation. In general, current techniques allow detenni-... 

Fragmentation experiments such as precursor ion scans using triple-stage quadrupole and ion trap mass spectrometers methods provide insights can identify conmiOTi and characteristic product ions and allow the detection of minor ergot alkaloids not included in routine analyses today. Ion trap detection allows several fragmentations (MSn experiments) that can enhance the ability to elucidate the structures of unknown ergot alkaloid derivatives. 

Polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs) are two classes of compounds that are of environmental concern because of the high toxicity of those isomers with 2,3,7,8-tetrachloro-substitution [12]. The PCDDs/PCDFs are monitored in air, rain, effluents, soil, and biota matrices. Usually, the total concentration of all PCDD/PCDF congener groups (i.e., total tetra-chlorinated dioxins, total pentachlorinated dioxins, etc.) and the concentrations of each of the seventeen 2,3,7,8-substituted toxic isomers are monitored. Such determinations require extensive sample preparation, sixteen expensive C 12-2,3,7,8-substituted internal standards [13], and mass spectrometers of high capital cost. High-resolution MS [14,15] or triple-stage quadrupole MS (TSQMS) [16-18] is necessary in order to differentiate between (1) PCDDs/PCDFs and interferences, such as polychlorinated biphenyls [19], and (2) Ci2-PCDFs and native PCDDs. 

---