The quartz-crystal microbalance (QCM) used in our experiments showed that a frequency change of 1 Hz corresponded to a mass increase of 1.05±0.01ng on the QCM electrode. The copolyamino acids adsorbed fenitrothion by as much as half of the mass. These results indicated that copolyamino acids had a high affinity for agricultural chemicals. And the adsorption to copolyamino acids was not only high but also rapid. The QCM method is required ouly for determining the microgram quantity of the adsorbents.
