posted on 2021-12-07, 14:42authored byWenyao Zhu, Frank Benkwitz, Bahareh Sarmadi, Paul A. Kilmartin
A new quantitative method based on
static headspace-gas chromatography-ion
mobility spectrometry (SHS-GC-IMS) is proposed, which enables the
simultaneous quantitation of multiple aroma compounds in wine. The
method was first evaluated for its stability and the necessity of
using internal standards as a quality control measure. The two major
hurdles in applying GC-IMS in quantitation studies, namely, nonlinearity
and multiple ion species, were also investigated using the Boltzmann
function and generalized additive model (GAM) as potential solutions.
Metrics characterizing the model performance, including root mean
squared error, bias, limit of detection, limit of quantitation, repeatability,
reproducibility, and recovery, were investigated. Both nonlinear fitting
methods, Boltzmann function and GAM, were able to return desirable
analytical outcomes with an acceptable range of error. Potential pitfalls
that would cause inaccurate quantitation, that is, effects of ethanol
content and competitive ionization, were also discussed. The performance
of the SHS-GC-IMS method was subsequently compared against that of
a currently established method, namely, GC–MS, using commercial
wine samples. These findings provide an initial validation of a GC-IMS-based
quantitation method, as well as a starting point for further enhancing
the analytical scope of GC-IMS.