scholarly journals Volumetric determination of zinc by the use of uranyl acetate, uranyl nitrate or ammonium molybdate test paper as an external indicator

1960 ◽  
Vol 9 (12) ◽  
pp. 1041-1044
Author(s):  
Tomoyuki MUKOYAMA ◽  
Norio ICHINOSE
1942 ◽  
Vol 15 (2) ◽  
pp. 382-390
Author(s):  
Willard P. Tyler

Abstract Two internal indicator volumetric methods for the determination of zinc in rubber compounds have been devised and investigated. The first method is a wet-oxidation method employing nitric acid, bromine, and perchloric acid as oxidants, and p-ethoxychrysoidine, a new oxidation-reduction indicator for this use, as indicator. It is of general application to all types of rubber compounds. The second method, less generally applicable to rubber compounds, utilizes either the new indicator or the well-known indicator, diphenylbenzidine. This method depends on ashing of the sample, and cannot be used for the analysis of zinc in rubber compounds containing lead or silicates, since it has been found that no method in which the sample is ashed yields accurate results if these substances are present. Both methods use potassium ferrocyanide as the volumetric precipitant and potassium ferricyanide as an integral part of the indicator system. Both methods are applicable to other organic and inorganic zinc-containing materials. The first method appears to have a slight advantage in ease of manipulation, total time of determination, and range of applicability. There is little choice between the methods or indicators as regards precision, accuracy, or the actual time used by the analyst for a determination, providing each method and indicator is used only under the proper conditions. Both methods are superior to the external indicator method using uranyl acetate, the method now in common use in rubber laboratories.


Author(s):  
Amankwah K.S. ◽  
A.D. Weberg ◽  
R.C. Kaufmann

Previous research has revealed that passive (involuntary inhalation) tobacco smoking during gestation can have adverse effects upon the developing fetus. These prior investigations did not concentrate on changes in fetal morphology. This study was undertaken to delineate fetal neural abnormalities at the ultrastructural level in mice pups exposed in utero to passive maternal smoking.Pregnant study animals, housed in a special chamber, were subjected to cigarette smoke daily from conception until delivery. Blood tests for determination of carbon monoxide levels were run at 15-18 days gestation. Sciatic nerve tissue from experimental and control animals were obtained following spontaneous delivery and fixed in 2.5% gluteraldehyde in 0.1M cacodylate buffer pH 7.3. The samples were post-fixed in osmium ferrocyanide (1:1 mixture of 1.5% aqueous OSO4 and 2.5% K4 Fe(CN)6). Following dehydration, the tissues were infiltrated with and embedded in Spurr. Sections were stained with uranyl acetate and lead citrate.


2020 ◽  
Vol 16 (1) ◽  
pp. 65-74
Author(s):  
Ortensia Ilaria Parisi ◽  
Mariarosa Ruffo ◽  
Fabio Amone ◽  
Rocco Malivindi ◽  
Domenico Gorgoglione ◽  
...  

Background: The Rotonda’s Red Eggplant belongs to the family of Solanum aethiopicum and it is cultivated in a specific area of Potenza (Basilicata, South of Italy) including villages of Rotonda, Viggianello, Castelluccio Superiore and Castelluccio Inferiore. The Red Eggplant cultivated in this area has gained the PDO, “Protected Designation of Origin”. Objective: The aim of this research was to evaluate the use of PDO Rotonda’s Red Eggplant extract as a possible nutraceutical supplement. The antioxidant, antihypertensive, hypoglycemic, and hypolipidemic properties were in vitro evaluated. Methods: The antioxidant activity was investigated by evaluating the scavenging properties against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals and by performing the Ammonium Molybdate and Folin-Ciocalteu assay. The hypoglycemic and antihypertensive activity was studied by evaluating the α-Amylase, α-Glucosidase and Angiotensin Converting Enzyme, respectively, inhibiting activity. In order to evaluate the hypolipidemic activity, the pancreatic lipase inhibiting property was determined and Oil Red O staining assay was performed. Finally, to evaluate the possible use of this extract as a minerals supplement, Selenium, Potassium and Chrome bioaccessibility was studied. Results: The obtained results underline the good antioxidant, hypoglycemic, antihypertensive and hypolipidemic in vitro properties of the PDO Rotonda’s Red Eggplant extract. Moreover, the obtained data show a higher minerals bioaccessibility and this higher value could be ascribable to the natural phytocomplex of PDO Rotonda’s Red Eggplant, which increases the minerals bioaccessibility if compare it with a control sample. Conclusion: The obtained results show that PDO Rotonda’s Red Eggplant extract, might be used as a possible nutraceutical supplement, along with traditional therapies, both for its biological properties and for its minerals bioaccessibility value.


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