A new spectrophotometric method for the determination of maneb in commercial formulations

A new rapid, selective and sensitive method has been developed for the dete rmination of maneb using pyrocatechol-violet(PV) as chelating reagent in th e pH range of 7.5-11.0 in the presence of CTAB producing a complex which sh ows maximum absorption at 640 nm. Working range of the method is 0.2-3.0 mu g ml(-1) maneb (manganese ethylenebisdithiocarbamate). The molar absorptivi ty of the color system is 79600 l mol(-1) cm(-1) and Sandell's sensitivity is 0.0033 mug cm(-2). The reproducibility of the method has been checked by the 10 replicate analysis of 15 mug of maneb in 10 mi of solution. The met hod is quite sensitive and has been applied for the determination of maneb in various commercial samples, crops, grains and synthetic samples.