Extraction spectrophotometric determination of maneb with 1-(2'-pyridylazo)-2-naphthol (PAN).
A rapid, sensitive, simple and selective spectrophotometric method has been developed for the determination of micro-quantities of maneb (manganese ethylenebisdithiocarbamate) after extraction of the manganese-PAN complex in isobutyl methyl ketone (MIBK). The complex absorbs strongly at 550 nm. Beer's law is obeyed over the concentration range 0.37-3.75 microg/ml. The molar absorptivity was found to be 4.1 x 10(4) l. mole(-1) . cm(-1). The developed method has been applied to the determination of maneb in commercial formulations, synthetic mixtures, grain and in the presence of various other dithiocarbamates.
A New Spectrophotometric Method for the Determination of Maneb in Commercial Formulations
Abstract A new rapid, selective and sensitive method has been developed for the determination of maneb using pyrocatechol-violet(PV) as chelating reagent in the pH range of 7.5–11.0 in the presence of CTAB producing a complex which shows maximum absorption at 640 nm. Working range of the method is 0.2–3.0 μg ml−1 maneb (manganese ethylenebisdithiocarbamate). The molar absorptivity of the color system is 79600 1 mol−1 cm−1 and Sandell's sensitivity is 0.0033 μg cm−2. The reproducibility of the method has been checked by the 10 replicate analysis of 15 μg of maneb in 10 ml of solution. The method is quite sensitive and has been applied for the determination of maneb in various commercial samples, crops, grains and synthetic samples.
Spectrophotometric determination of manganese with thenoyltrifluor-acetone
Abstract A new spectrophotometric method for the determination of microgram amounts of manganese with thenoyltrifluoracetone(TTA) is described. After oxidation with sodium bromate, manganese (presumably tervalent) is extracted with 0·5 M TTA in xylene from a 0·5 M sulphuric acid solution. The absorbance of the organic phase is measured at 440 or 450 mμ. Beer's law is followed up to 10 μg of manganese/ml of organic phase. Except for cerium, iron and chloride, small amounts of many common elements do not interfere. Iron(III) can be removed by cupferron-chloroform extraction, and cerium by washing the TTA extract with an ammonium hydrogen fluoride-nitric acid solution.