Method-performance studies of notified analytical method for fenbutatin oxide and cyhexatin

Method-performance studies were conducted for the notified revised analytic al method of fenbutatin oxide (FBTO) and cyhexatin (CHT). FBTO and CHT spik ed into rice, soybeans, spinach, orange, tea powder and tea extract at the level of 0.5 mug/g for FBTO and 0.1 mug/g for CHT were analyzed in replicat e in 6 laboratories. Means recoveries of FBTO were 85.2 similar to 96.5% and those of CHT were 8 3.5 similar to 89.2% except from soybeans (46.5%). Repeatability relative s tandard deviation values of FBTO and CHT in each crop were in the ranges of 2.3 similar to9.4% and 3.2 similar to6.3%, respectively. Reproducibility r elative standard deviations were 3.9 similar to 12.6% for FBTO and 8.3 simi lar to 12.9% for CHT. Detection limits were 0.015 similar to0.05 mug/g for FBTO and 0.005 similar to0.02 mug/g for CHT.