Joint approximate diagonalization of eigenmatrices (JADE) for the analysis of comprehensive two-dimensional gas chromatographic data

Comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometer (GC×GC-TOFMS) has been emerged as the most powerful analytical methodology nowadays available for the analysis of target compounds in complex samples because of its high resolution and high peak capacity [1]. However, complete separation of all detectable components cannot be achieved because of the extremely high complexity of analytical samples and because of limitations in experimental and instrumental conditions. Chemometric resolution techniques can be used to address incomplete separation issues [2]. In the present contribution, joint approximate diagonalization of eigenmatrices (JADE) as a member of independent component analysis (ICA) family is proposed for the analysis of GC×GC-MS data. In this regard, different two- and three-component GC×GC-MS data sets were simulated. Then, GC×GC-MS data sets were column-wise super-augmented and analysed by JADE algorithm. Statistical parameters of lack of fit (LOF), mutual information (MI) and amari index were used for evaluation of the performance of JADE algorithm [3]. In addition, MCR-BANDs and FAC-PACK methods were used for calculation of the extent of rotational ambiguity in the data. Inspection of the results showed the good performance of JADE for the analysis of GC×GC-MS data. In addition, the JADE solutions were in the range of feasible solutions in all studied cases. Moreover, the performance of JADE was compared with multivariate curve resolution-alternation least squares (MCR-ALS) and other ICA algorithms of mean-field ICA (MFICA) and mutual information least dependent component analysis (MILCA) in terms of statistical parameters and calibration analytical figures of merit (AFOMs). Finally, JADE algorithm was used for resolution and quantification of phenanthrene and anthracene in aromatic fraction of heavy fuel oil (HFO) analyzed by GC×GC-MS. Surprisingly, pure elution and spectral profiles of target compounds were properly resolved in the presence of baseline and interferences using JADE. Also, the performance of JADE in real case was compared with MCR-ALS. On this matter, the MI values were 1.01 and 1.13 for resolved profiles by JADE and MCR-ALS, respectively. In addition, LOD values (µg/mL) for phenanthrene were respectively 1.36 and 1.24 and for anthracene were respectively 1.26 and 1.09 using MCR-ALS and JADE which showed outperformance of JADE over MCR-ALS. It is concluded that JADE can be used as an alternative method for analysis of GC×GC-MS data of complex samples.