The Column - June 2009 - 15

The Column www.thecolumn.eu.com Rainville and Mather Experimental Results As seen in Figure 3, during the development of an LC–MS–MS method for ﬂuticasone Figure 3: Analysis of rat plasma spiked with 100 ng/mL ﬂuticasone propionate. Figure 2: Schematic illustrating PIC data acquisition. MRM m/z 501 100 % 169.1 200 0 100 % The collision cell design of the tandem quadrupole MS allowed for simultaneous acquisition of both MRM and full scan MS data. PIC takes advantage of this capability to collect a high-quality full scan MS or MS–MS spectrum during MRM acquisition.1 This MS or MS–MS spectrum is acquired after the apex of the MRM peak and before the return to baseline. (See Figure 2) Furthermore, the fast data capture rate of the tandem quadrupole MS allowed for multiple full scan MS or MS–MS spectra to be acquired across the narrow, 2- to 3-second-wide chromatographic peaks that are typically generated during analysis when coupled with UPLC. propionate, two peaks with the same MRM transitions were detected. Also seen in Figure 3 was the product ion scan spectra simultaneously generated by the PIC function during analysis. Spectra (a) is that obtained from the peak eluting with a retention time of 0.69 minutes and spectra (b) was obtained from the peak eluting with a retention time of 0.85 minutes. Each of the product ion scan spectra generated from the analysis were then compared with the product ion scan spectra obtained during sample tuning of the ﬂuticasone propionate standard as seen in Figure 4. The comparison of the two spectra shows good agreement, conﬁrming that the peak with the retention time of 0.85 minutes is the analyte of interest, ﬂuticasone propionate. Thus it was demonstrated that in one analytical run, we were able to identify the peak at 0.85 minutes as the analyte of interest without the need for further analysis. Conclusion Multiple peaks with the same MRM transition can be observed during method development or routine analysis in bioanalytical studies. These spurious peaks can be generated by chromatographic peak splitting, metabolites or matrix interferences. PIC functionality enables the conﬁrmation of peak identity during MRM quantitative analysis by obtaining a quality product scan spectra during MRM MS analysis. The ability of the tandem quadrupole MS to perform this function results in the reduction of further conﬁrmatory experiments, saving time and money, which ultimately increases laboratory productivity. Furthermore, this function can be performed with the narrow, 2- to 3-second-wide chromatographic peaks generated by UPLC. Figure 4: (a) Product scan comparison of ﬂuticasone propionate standard and (b) product scan acquired by PIC of analyte peak eluting at 0.85 min. 100 (a) 0 50 100 150 200 250 300 m/z 350 400 450 500 Reference 1. M. Twohig et al., Simultaneous Conﬁrmation and Quantiﬁcation using Xevo TQ MS: Product Ion Conﬁrmation (PIC), Waters Application Note 720002829en (2008). 100 301008_PICS_55 1:39 0.85 (a) 1:MRM of 1 Channel ES+ TIC (ﬂuticasone) 3.67e4 (b) 293 255.1 255.7 314.8 331.8 300 400 474.7 500 m/z (b) % MRM m/z 501 293 % Daughter full MS scan MRM m/z 501 MRM m/z 501 293 1 2 3 4 5 6 7 8 9 101112 293 293 0 0.20 0.40 0.69 MRM m/z 501 Scans 0.60 0.80 1.00 Time (min) 1.20 1.40 0 50 100 150 200 250 300 m/z 350 400 450 500 Paul D. Rainville is a senior applications chemist working in the Waters Pharmaceutical Business Operations group. Paul has been with Waters for over seven years and has worked in a variety of application areas including biomolecule separations, 15 1 9 Contents Tips & Tricks 2 13 Vosloo Rainville and Mather 6 17 News Meeting Review 8 20 Market Trends & Analysis Events & Contacts
The Column - June 2009

Table of Contents for the Digital Edition of The Column - June 2009
