Determination of manganese with crystal violet in plant material in different fertilization

D.Kostova, M.Kamburova

Agricultural University – Plovdiv
12, Mendeleev Str., 4000 Plovdiv, Bulgaria
E-mail: deny_kostova@yahoo.com

Abstract:

A study in a multiple-factor stationary field experiment with 16 variants NPK on background with and without annual fertilization with manure was carried out at the Agricultural University in Plovdiv, Bulgaria. The manganese content in the roots of radishes, cultivar Red with white tails, was determined by a new extraction-photometric method with Crystal Violet. The ion-associate of manganese (VII) was completely extracted in a single extraction of only 30 s. The molar absorptivity of the associate was (1.54 ± 0.05) x 104 l mol-1 cm-1. This indicates the high sensitivity of the given reaction. Manganese has been determined by atomic-absorption method, too, in order to compare the results. It was established that fertilization has an effect upon the manganese content in the roots of radishes. The roots of radishes accumulate the highest level of manganese 116.25 mg/kg in a mineral fertilization N:P:K = 3:2:1 with 40 t/ha manure. The relationship between yield and manganese content in radish roots under the influence of fertilization has been established.

Key words:

Crystal Violet, fertilization, manganese determination, plants

Determination of manganese with Methylene Blue in various vegetable crops

H.P. Beck, D. Kostova and B. Zhang

Inst. Inorg. Anal. Chem. Radiochem.,Saarland Univ. Saarbrucken, D-66123, Germany

Abstract:

A study was made of the manganese content in the crop production of 28 vegetable species, using the most common cultivars within the species. The manganese content was determined by a new extraction – spectrophotometric method using Methylene Blue (MB). The ion – associate of Mn(VII) was completely removed in a single extraction of only 5 s, and the 1,2-dichloroethane layer remained constant for 2 days under the usual laboratory conditions. To compare results, manganese was determined by the atomic – absorption method. The results obtained showed that the manganese content varies significantly in the different vegetable species and cultivars. The manganese content in more widely used varieties of tomatoes, peppers, head cabbage, melons, and radishes was studied in order to establish differences with respect to the level of this element in their production.

Key words: