Abstract
The various methods used to estimate chlorophyll are summarized, with procedure (and graphs) for comparing results colorimetrically and spectrometri-cally. The colorimetric method is most accurate ([plus or minus]3.3%) at chlorophyll concentrations of about 0.05 gm. per liter while the spectrometric method is most accurate ([plus or minus]5%) at concentrations of 0.10-0.15 gm. per liter. The stability of K-chlorophyllin is discussed.