Chemometrics in instrumental analysis of complex systems—in honor and memory of Yi-Zeng Liang

A true pioneer in the fields of chemometrics and analytical chemistry was lost with the passing of Yi-Zeng Liang in October 2016. This is an enormous loss to both the local and global community of chemometrics. Yi-Zeng Liang is recognized as one of the major players in China in the field of chemometrics. As a professor of chemometrics and analytical chemistry in Hunan University and Central South University, he made significant advances within instrumental analysis of complex systems. Liang inspired many students and visiting scholars. As Liang's former students, we have attempted to summarize Liang's contributions to the field over the past 30 years. This review covers different chemometric areas, signal preprocessing, multivariate curve resolution, and multivariate calibration and discusses the application of these methods in traditional Chinese medicine, metabolomics, proteomics, and quantitative structure-activity relationship research.