The earliest analytical methods based on chemical kinetics???which first appear in the late nineteenth century???took advantage of the catalytic activity of enzymes. Despite the diversity of chemical ...The earliest analytical methods based on chemical kinetics???which first appear in the late nineteenth century???took advantage of the catalytic activity of enzymes. Despite the diversity of chemical kinetic methods, by 1960 they no longer were in common use. By the 1980s, improvements in instrumentation and data analysis methods compensated for these limitations, ensuring the further development of chemical kinetic methods of analysis.