The application of multivariate curve resolution-correlation optimized warping method for simultaneous solving coelution and time shift-related artifacts in complex GC-MS signals; toward obtaining the through comparative study of chemical variability of citrus aurantium L. peel samples

Multivariate curve resolution of the coeluted multicomponent signals based correlation optimized warping (MCR-COW) was proposed as an efficient alignment method in correcting the undesirable elution time shifts where coeluting and shift occurred at the same time and the use of COW algorithm on the raw data often fails [1]. For this purpose, the primarily implementation of extended multivariate curve resolutionalternating least square in a multiset analysis of three samples helped to reduce the underlying complexity of GC-MS data representing the pure elution and spectral signatures. Afterward, the resolved elution profiles aligned component by component using COW algorithm. Reconstituting of the corrected multiset data was conducted by multiplying of aligned augmented elution profiles with their spectral profiles to reanalysis by MCR-ALS under triliearity constraint [2]. The results obtained from the proposed strategy (MCR-COW-MCR) compared to two common methods MCR-ALS and COW-MCR under application of the same constraints in statistical terms such as lack of fit (LOF), percent of variance explained by model (R2) and spectral correlation coefficient (R). Inspection of the results shows that by avoiding of aligning the non-corresponding elution information and improving the initial application of COW algorithm in MCR-COW-MCR method, the quality of the chemical variability of the chromatographic profiles related to the constituents of three varieties of citrus aurantium L. peel extracts were correctly assessed by PCA modeling. Hereby, the presented strategy by improving the accuracy of quantitative and qualitative results provided an opportunity to reach a comprehensive comparative study from the composition and content of volatile constituent s points of view in the studied samples. According to the obtained results, it can be concluded that relevant similarities among volatile constituents of desired varieties related to the predominant presence of monoterpene and sesquiterpene hydrocarbons. In addition, the oxygenated compounds derived from these hydrocarbons in relatively low content were considered as an indicator of high quality of peel samples [3]. On account the highest content of oxygenated compounds in variegated sour orange in comparison to other verities, it can be concluded that the variety can affect the amount of oxygenated compounds and as a result on the sample quality. Furthermore, each variety contains the constituents in minor quantities that differ between them and can be used in identifying and authenticity the various extracts because of they are responsible for the specific flavor and odor of citrus fruits.