Fluoride pollution in ground waters of Kandukur revenue Sub-Division of Prakasam district in A.P., India and batch mode defluoridation using active carbons of some plant byproducts as adsorbents.

Fluoride is an acute toxin and is deemed to be slightly more dangerous than even lead. 48 water samples collected from hand pumps and bore wells belonging to 24 gram panchayats (villages) of Kanduku revenue sub division of Prakasam district in Andhra Pradesh, were chemically analyzed for fluoride ion concentrations. High and low fluoride containing regions were identified on the basis of fluoride levels in the water samples and also on the prevalence rate of dental and skeletal fluorosis of the study area. Further, water samples containing high fluoride levels were tried for defluoridation by employing Active Carbons of abundantly available low-cost plant byproducts. These materials under optimum conditions of adsorbent dosage, time of equilibration and pH, were found to be successfully decreasing the fluoride ion concentration below permissible limits without disturbing drinking water quality standards.

Validation of defluoridation method with “acacia arabica” plant byproduct through 2n factorial experimentation-A statistical approach.

Adsorption is one of the most efficient physicochemical processes known to remove fluoride from drinking water. Activated carbon adsorption is conventionally the most used material for this purpose. The aim of this study was to know the variables that influence the adsorption process of fluoride ion from aqueous media, so as to optimize the operating conditions. Factorial experimentation within a certain domain was used to determine the influence level of several parameters, such as initial pH of the solution, particle size, adsorbent’s concentration agitation time and their interactions. A statistical analysis of the results showed that within the selected domain all the parameters have influence at a significance level of 1% excepting initial pH that only has influence at a significance level of 5 %. Some of the possible interactions between these parameters also have significant influence on the adsorption process especially first order ones, including significance levels of 5 and 1%. This means then that optimization of operating conditions water treatment using the studied adsorption technique will not imply additional costs. This emphasizes the importance of Acacia arabica fruit carbon as an alternative to activated carbon.

Validation of new spectrophotometric methods for quantitative determination of 7-ADCA in pharmaceutical formulations.

Three simple, sensitive and accurate methods are described for the determination of 7-Amino deacetoxy cephalosporanic acid (7-ADCA) in bulk drug and in formulations. Methods Ma to Mc are based on Redox / complex formation reaction between 7-ADCA and ammonium Molybdate and sulphuric acid (AM/H2SO4) (Ma), Ferric chloride/ Ortho Phenonthraline (Fe+3/o-Phen)(Mb) and FeCl3/potassium Ferricyanide (Fe+3/K3Fe(CN)6) (Mc) solutions. The chromogen being extractable with chloroform could be measured quantitatively at 625 (Ma), 510 (Mb) and 740 nm (Mc). All variables were studied to optimize the reaction conditions. Regression analysis of Beer's Law plot showed good correlation in the concentration ranges 10-60 for Ma, 1.25-7.5 for Mb and 2.5-15 mg/ml for Mc. The calculated molar absorptivity values are 2.835 x 103, 2.277 x 104, and 1.715 x 104 L/mol/cm for Ma to Mc, respectively. The methods were successfully applied to the determination of 7- ADCA in formulations and the results tallied well with the label claim. The results were statistically compared with those of a literature method by applying the student’s t-test and F-test. No interference was observed from the concomitant substances normally added to preparations. The accuracy and validity of the methods were further ascertained by performing recovery experiments via standard-addition method.

Spectrophotometric determination of fluvoxamine as maleate by selective methods.

Simple, accurate and reproducible visible spectrophotometric methods for the assay of drug fluvoxamine as maleate were established based on the formation of oxidative coupling reaction between the corresponding drug, Brucine-NaIO4 and DCQC. The procedures described were applied successfully to the determination of the compound in their dosage forms. The results showed that the proposed procedures compared favorably with the reference methods and satisfactory sensitivity, accuracy and precision. The optical characteristics such as Beer’s law limits, molar absorptivity and sandell’s sensitivity are reported. Regression analysis using the method of least squares was made to evaluate the slope (b), intercept (a) and correlation coefficient (r) and standard error of estimation (Se) for the drug.

Chemical examination of medicinal plant “caralluma umbellate” (asclepiadaceae) roots.

Two new pregnane compounds named as 3b-hydroxy-pregn-5-ene (CRUR I) and 3b,14 b-dihydroxy pregn-5-ene (CRUR II) were isolated from Caralluma umbellata roots and their structures elucidated by extensive spectroscopic studies like IR, H1, C13- NMR, and MS .