Reactant ion peak, RIP

Fig. 18. Overlay of plots from DMS-IMS2 response to several nitrotoluenes [2-mononitrotoluene (2-MNT), 3-MNT, 2,4-dinitrotoluene (2,4-DNT), 3,4-DNT, 2,4,6-trinitrotoluene (TNT)] in positive polarity (left). A reactant ion peak (RIP) is seen at 6.5 V and 1.9 ms, whereas protonated monomers are seen near 3 V and 2.2ms, and proton-bound dimers are at 0V and 3.5ms. TNT does not show a response in positive polarity. Overlay of plots from DMS-IMS2 response to several nitrotoluenes (cf. list in positive polarity) in negative polarity (right). A RIN is seen at 7 V and 1.8 ms, whereas molecular adducts or charge-exchanged ions are seen at 0.5 V and 2.5 ms. MNTs do not show a response in negative polarity. Source Neil D. Paz, NMSU...

Three ion peaks are seen in this mobility spectrum. The first, at a drift time of about 6 ms, is called the reactant ion peak (RIP) and is present in the spectrum even when a sample is not. The next two ion peaks are ion peaks of 4,6-dinitro-o-cresol, a common contaminant from smoke, with a reduced mobility of 1.59 V cm s and 2,4,6-trinitrotoluene (TNT) with a reduced mobility of 1.54 V cm s. For... 

Mmiaturized Ion Mobility Spectrometry, Fig. 2 Ion mobility spectrum of 100 ng trinitrotoluene as analyzed by Itemiser (GE-Interlogix), a commercial ion mobility spectrometer. Two peaks were observed, the chloride reactant ion peak (RIP) and the trinitrotoluene (TNT) peak. The TNT peak had a drift time of 5.35 ms, with a peak width of 0.34 ms... 

Figure 16.7—Ion mobility spectrometer. Ions enter the analyser tube by control of the polarity of the acceleration grid. An example of a recording in the repetitive mode (RIP Reactant Ion Peak) for tolyl isocyanate (TDI), the compound analysed, is shown. A commercial model of an Environmental Vapour Monitor is also shown (reproduced by permission of Grasby Electronics, UK). This instrument uses a GC column to improve compound identification.

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