Column chromatographic separation of lead(II) using poly [dibenzo-18-crown-6] in L-ascorbic acid.

A column chromatographic separation method has been developed for separation of Lead(II) using poly[dibenzo-18-crown-6]. The separation was carried out in L-ascorbic acid medium. The adsorption of Lead(II) was quantitative from 1 x 10(-2) M to 1 x 10(-7) M L-ascorbic acid. The capacity of poly [dibenzo-18-crown-6] for Lead (II) was found to be 0.530 +/- 0.01 mmol/g of crown polymer. Lead(II) was separated from commonly associated metal ions such as Mg(II), Co(II), Ni(II), Cd(II), Mn(II) Th(IV) and U(VI) and other associated metal ions in binary as well as in multicomponent mixtures. The sorption of Lead was carried out in presence of various ions to ascertain the tolerance limits of individual. The method was extended for the determination of Lead in real samples. The method is simple, rapid and selective having good reproducibility (approximately +/- 2%).

Lake contamination by accumulation of heavy metal ions in Eichhornia crassipes: a case study of Rankala Lake, Kolhapur (India).

The absorption of heavy metals into biomaterial derived from the plant Eichhornia crassipes was investigated. The root, stem and leaf samples of the plant collected from the Rankala Lake of Kolhapur city (India) were analyzed for the metal ion concentrations using Atomic Absorption Spectrometer. It has been observed that in root, stem and leaf, Pb ions get absorbed, while the extent of absorption for each element found different in the parts analyzed. In root, the order for metal ion absorption found to be Fe>Mn>Cu>Zn>Cr>Pb>Ni>Co>Cd ions. Thus, it is clear that Eichhornia crassipes absorbs heavy metal ions and can be used for minimizing the pollution taking place due to toxic metal ions in the effluents from various industries.

Column chromatographic separation of molybdenum (VI) from alloys with poly-(dibenzo-18-crown-6) from a hydrochloric acid medium.

A very simple column chromatographic separation method has been developed for molybdenum (VI) using poly-(dibenzo-18-crown-6). The separations are carried out from hydrochloric acid medium. The adsorption of molybdenum (VI) on a poly-(DB-18-C-6) was quantitative from 2.5 to 10.0M HCl. Amongst the various eluents tested, 0.5M ammonium hydroxide was found to be an efficient eluent. Molybdenum (VI) was separated from a large number of elements in binary form, as well as from multicomponent mixtures. The method was applied for the analysis of molybdenum from various alloy samples. The method is very simple, rapid, selective and reproducible. The reproducibility of the procedure is +/-2%.

Solvent extraction separation of rubidium with dicyclohexano-18-crown-6.

Rubidium is extracted quantitatively at pH 3.0-7.0 by 0.01M dicyclohexano-18-crown-6 in methylene chloride from 0.01M picric acid, stripped with 2M nitric acid and determined by flame photometry or atomic-absorption spectrometry. It can be separated from the most alkali and alkaline-earth metals, but the tolerance levels for potassium, ammonium and barium are rather low. The common anions, including those of some organic acids, are tolerated in fairly high amounts. The method has been applied to analysis of chloride schist rock and lepidolite for rubidium. The analysis takes an hour.