Page 345 - CRFTApplication Compendium_090613

After analysis of the human urine
samples, the chromatographic peaks
were integrated and the peak areas
were used to perform regression
analysis. A representative calibration
line is shown in Figure 6. The inset
shows the calibration line between
the LLOQ (0.5 ng/mL) and 5 ng/mL.
Quality control samples were
analyzed as shown in Table 2.
Combining FAIMS with H-SRM
provides excellent selectivity, which
results in improved accuracy and
precision at the LLOQ.
The interferences that result in
31% RSD and –20% accuracy are
removed using FAIMS and H SRM.
The final precision is 12% RSD and
the accuracy is 8% of theoretical.
Conclusion
The combination of FAIMS and
H-SRM provides excellent selectivity
for the analysis of clenbuterol in
human urine. Compared to the
LC–SRM method, the use of
LC–FAIMS–H-SRM reduced the
chemical background and resulted
in cleaner chromatograms and more
reproducibly integrated chromato-
graphic peaks. At the LLOQ, the
clenbuterol assay in human urine
shows the best accuracy and precision
via LC–FAIMS–H-SRM.
100
90
80
70
60
50
40
30
20
10
00.0 0.5 1.0 1.5
Time (min)
2.0 2.5 3.0
RT: 1.8
AA: 23673
RelativeAbundance
Figure 4: Representative LC–FAIMS–SRM chromatogram for clenbuterol in human urine, obtained
with unit resolution and with FAIMS selectivity
100
90
80
70
60
50
40
30
20
10
0
RT: 1.8
AA: 9258
0.0 0.5 1.0 1.5
Time (min) 2.0 2.5 3.0
RelativeAbundance
Figure 5: Representative LC–FAIMS–H-SRM chromatogram for clenbuterol in human urine, obtained
with high (0.1 FWHM) resolution combined with FAIMS selectivity.