The normalization part of MS-DIAL and MRMPROBS programs was separated. The powerful mathematics especially for cohort studies is essential to normalize the drifts of MS-signal intensities. The basic concept of this method is to use the intensities over an analytical run of 'quality control (QC)' sample which is a mixture of all biological samples.

Briefly, measurement data of QC samples are smoothed by the LOWESS of the single-degree least-squares. And then, the coefficient values between QC samples are interpolated by the cubic spline. Lastly, the entire datasets is aligned to the spline result.

Principal component analysis (PCA), projection to latent structure regression (PLS-R), and projection to latent structure based discriminant analysis (PLS-DA) are the commonly-used multivariate analysis method in metabolomics study. Of course, there are many platforms for these analyses not only by the commercially available software such as SIMCA-P, but also by freely available software such as statistical language R, MetaboAnalyst. I also use them very much! However, I think that excel based platform should be also required for the approachability and the easily adjustment of Figures. In addition to multivariate analysis, I think that the easy-to-use platform for the graph making and the multiple comparison method is also required although I also know these tasks are possible by some tools like VANTED. I would like to offer the platform such that many researchers can easily do the statistical analysis.

Methoxyamine hydrochloride (MeOX) and N-Methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) are commonly used for the derivatization of small molecules to decrease boiling points and increase stability for GC-MS analysis. Therefore, it is important to theoretically consider the TMS- and MeOX form of small molecules to predict their retention time- and fragmentation behaviours as well as to calculate their chemical properties. Therefore, the converter from the original structure form to the MeOX- and TMS derivative structure was developed. This converter accepts the SMILES code for structure description, and it generates the derivatized form as SMILES.