Biomedical Engineering Reference
In-Depth Information
Figure
11.7.
1
H NMR (top) and HQSC NMR spectra (bottom) for a representative hydrolysate
sample. Numbers indicate distinct functional groups or compounds that account for the signal.
(See the insert for color representation of this figure.)
(Fig. 11.8, bottom). Next, PCA was used to identify peaks in the HSQC spectra that
vary from lot to lot (Fig. 11.8, top). Peaks in the 1-D PLS correspond to a set of
peaks in the 2-D spectra. Some of these peaks were identified while others could be
prioritized for identification based on the correspondence between the 1-D and 2-DNMR
results.
The correlation between
1
H
NMR PLS scores and cell-culture performance is at
least 0.5 (Table 11.2), rivaling the correlation of Zn. The types of compounds measured
by ICP-MS and NMR are different; therefore, combining results from these techniques
would increase the variables used to predict performance of a raw material. Combining
scores from
1
H
NMR and Zn may improve the predictive ability of the method and
eliminate the need for routine use testing.
Table 11.2 points to three correlations. The last of these is an ion detected by LC-MS.
The ion with m/z 279.17 has a consistent negative correlation with cell growth. When
combined with the Zn concentration determined by ICP-MS, more variation is explained
in a multilinear regression model. Likewise, by combining NMR and Zn results, the
probability that the analytical testingwouldmatch that of the use test is increased. Efforts
