LAUSR

It was with great regret that we received the incredibly sad news of the untimely death of Professor Ronei Jesus Poppi (Figure 1), on the last April 25 in the city of Campinas, S~ao Paulo State, Brazil. Ronei was born on the outskirts of Campinas, son of barber and a housewife, in a lower middle-class family. In 1986, he earned a bachelor's degree in Chemistry at the State University of Campinas (UNICAMP). In 1989, he obtained a master's degree at the same university under the supervision of Professors José Fernando Faigle, already deceased, and Roy Bruns, with a dissertation on the quantification of analytes with overlapped chromatographic peaks by multivariate calibration. This was a pioneering study in multivariate calibration in Brazil and South America, resulting in the first Brazilian/South American article to apply partial least squares (PLS) and principal component regression (PCR), published in the Journal of Chromatography in 1991. It is important to highlight that the start of chemometrics in Brazil had taken place only some years before, in the beginning of the 1980s, when Prof. Bruns invited Bruce R. Kowalski who gave a course on chemometrics during a month stay at UNICAMP, and initiated his landmark studies in this country. Ronei started to work on his master's degree in 1986 and accepted the challenge to do research in multivariate calibration that was a relatively new subject with very few publications at the time. Toluene, isooctane, and ethanol mixtures were analyzed by gas chromatography with a simple thermal conductivity detector. The effects of different degrees of overlap on calibration and prediction errors were investigated using chromatograms obtained at different column temperatures. At that time, peak heights and areas were not registered digitally, and Ronei used a simple ruler to measure 41 chromatographic response values at different retention times for all the calibration and validation samples. The PLS calculations were carried out on an 8-bit DICON microcomputer with an 8-inch 32-kB floppy disk for memory space using the SIMCA3B program. PCR regressions were made with home-made software on a PC-XT that was the successor of IBM's first PC and had 5 and 1/4 inch removable disks and a hard disk with 256 kB of memory. Work was done in a DOS environment before Windows operating systems became available. It was hard to attract analytical chemistry students to work in chemometrics in the 1980s because the mathematical methods were intimidating and computational tools very limited. In fact, chemometrics was not very well regarded by the most classical analytical chemists in Brazil at the time of the beginning of his career. But this did not deter Ronei who did much to help consolidate progress in chemometrics in Brazil. Even at such an early point in his career Ronei expressed his desire to form his own research group and work with students.