Isolation and staining of wheat transfer cells

1978 ◽  
Vol 56 (16) ◽  
pp. 1992-1995 ◽  
Author(s):  
S.-Y. Zee
Keyword(s):  
Chromium Trioxide ◽  
Potassium Dichromate ◽  
Transfer Cells ◽  
Ammonium Dichromate ◽  
Basic Dyes ◽  
Nodal Tissue

Xylem and phloem transfer cells in the vegetative nodes of wheat, fixed in a mixture of 3% ammonium dichromate + 3% potassium dichromate and 20% formalin (1:1), could be easily separated from the nodal tissue using a mixture of 2% chromium trioxide + 8% H2SO4 + 3% HNO3 solution. After maceration and staining (with either acidic or basic dyes), the well organized protoplast and the weakly birefringent walls of the transfer cells could be seen clearly.

Densities and Viscosities of Chromium Trioxide + Potassium Chromate + Potassium Dichromate + Water from (298.15 to 333.15) K

2008 ◽  
Vol 53 (3) ◽  
pp. 648-653 ◽  
Author(s):  
Ji-yan Wang ◽  
Fu-an Wang ◽  
Peng Zhang ◽  
Cheng-wei Li ◽  
Bao-zeng Ren
Keyword(s):  
Chromium Trioxide ◽  
Potassium Dichromate ◽  
Potassium Chromate

scholarly journals Application of Inorganic Oxidants to the Spectrophotometric Determination of Ribavirin in Bulk and Capsules

2006 ◽  
Vol 89 (2) ◽  
pp. 341-351 ◽  
Author(s):  
Ibrahim A Darwish ◽  
Alaa S Khedr ◽  
Hassan F Askal ◽  
Ramadan M Mohamed
Keyword(s):  
Ammonium Sulfate ◽  
Acid Medium ◽  
Chromium Trioxide ◽  
Potassium Dichromate ◽  
Ammonium Molybdate ◽  
The Other ◽  
Potassium Iodate ◽  
Potassium Periodate ◽  
Spectrophotometric Methods

Abstract Eight spectrophotometric methods for determination of ribavirin have been developed and validated. These methods were based on the oxidation of the drug by different inorganic oxidants: ceric ammonium sulfate, potassium permanganate, ammonium molybdate, ammonium metavanidate, chromium trioxide, potassium dichromate, potassium iodate, and potassium periodate. The oxidation reactions were performed in perchloric acid medium for ceric ammonium sulfate and in sulfuric acid medium for the other reagents. With ceric ammonium sulfate and potassium permanganate, the concentration of ribavirin in its samples was determined by measuring the decrease in the absorption intensity of the colored reagents at 315 and 525 nm, respectively. With the other reagents, the concentration of ribavirin was determined by measuring the intensity of the developed colored reaction products at the wavelengths of maximum absorbance: 675, 780, 595, 595, 475, and 475 nm for reactions with ammonium molybdate, ammonium metavanidate, chromium trioxide, potassium dichromate, potassium iodate, and potassium periodate, respectively. Different variables affecting the reaction conditions were carefully studied and optimized. Under the optimum conditions, linear relationships with good correlation coefficients (0.99840.9998) were found between the absorbance readings and the concentrations of ribavirin in the range of 41400 g/mL. The molar absorptivities were correlated with the oxidation potential of the oxidants used. The precision of the methods were satisfactory; the values of relative standard deviation did not exceed 1.64%. The proposed methods were successfully applied to the analysis of ribavirin in pure drug material and capsules with good accuracy and precision; the recovery values were 99.2101.2 0.481.30%. The results obtained using the proposed spectrophotometric methods were comparable with those obtained with the official method stated in the United States Pharmacopeia.

Some Observations on the Szilard-Chalmers Process in Dichromates

1963 ◽  
Vol 2 (2) ◽  
Author(s):  
T. Andersen ◽  
A. G. Maddock
Keyword(s):  
Solid Solutions ◽  
Potassium Dichromate ◽  
Ammonium Dichromate ◽  
Aqueous Method

SummaryThe initial retentions of samples of monoclinic and triclinic potassium dichromate, irradiated under the same conditions, were found to be 82.4 and 89.5% respectively. Monoclinic solid solutions of KAn entirely non-aqueous method of determining the retention in ammonium dichromate gave the same value as the aqueous procedure.

Untersuchungen über Isopolychromate

1968 ◽  
Vol 23 (9) ◽  
pp. 1137-1144 ◽  
Author(s):  
O. Glemser ◽  
W. Höltje ◽  
M. Stockburger
Keyword(s):  
Raman Spectroscopy ◽  
Absorption Spectrum ◽  
Raman Spectrum ◽  
Aqueous Solutions ◽  
Chromium Trioxide ◽  
Potassium Dichromate ◽  
The State ◽  
Laser Raman Spectroscopy ◽  
Laser Raman ◽  
Infra Red

The infra-red absorption spectrum and laser raman spectrum of crystalline potassium trichromate are reported and compared with the corresponding spectra of potassium dichromate. It is shown that the state of aggregation of acid and concentrated aqueous chromate solutions can be investigated by use of laser raman spectroscopy. Trichromate ions are found to exist in acid dichromate solutions having concentrations ≧ 3 M and acidity pH ≪ 0, and in aqueous solutions of chromium trioxide provided concenrations are ≧ 2 M.

ON THE OXIDATION OF 1, 1, 1-TRICHLORO-2,2-BIS- (p-TOLYL) -ETHANE

1953 ◽  
Vol 31 (1) ◽  
pp. 4-8 ◽  
Author(s):  
Yvon Perron
Keyword(s):  
Acetic Acid ◽  
Sulphuric Acid ◽  
Glacial Acetic Acid ◽  
Chloral Hydrate ◽  
Chromium Trioxide ◽  
Condensation Product ◽  
Potassium Dichromate ◽  
Oxidative Degradation ◽  
Amide Derivatives ◽  
Derivatives Of

The condensation of benzene with chloral hydrate in the presence of concentrated sulphuric acid gave rise to 1,1,1-trichloro-2,2-bis-(p-tolyl)-ethane. The oxidation of this condensation product with potassium dichromate in dilute sulphuric acid at the boiling temperature yielded 1,1-dichloro-2,2-bis-(p-carboxyphenyl)-ethylene, the structure of which was shown by its oxidative degradation to 4,4′-dicarboxybenzophenone. When the oxidation of the same condensation product was carried out in the cold, with the aid of chromium trioxide in glacial acetic acid and acetic anhydride, 1,1,1-trichloro-2,2-bis-(p-carboxyphenyl)-ethane was obtained in a good yield. This last compound was converted to the dichloroethylenic-dicarboxylic acid upon refluxing with a methanolic solution of sodium hydroxide. The corresponding amide derivatives of both the dichloro and trichlorodicarboxylic acids were also prepared.

scholarly journals Genetic effects of potassium dichromate and chromium trioxide in Drosophila melanogaster.

CYTOLOGIA ◽  
1986 ◽  
Vol 51 (3) ◽  
pp. 421-425 ◽  
Author(s):  
Rosario Rodriguez-Arnaiz ◽  
Rene Fernando Molina Martinez
Keyword(s):  
Drosophila Melanogaster ◽  
Chromium Trioxide ◽  
Potassium Dichromate ◽  
Genetic Effects

Preparation of Thin Cadmium Telluride Samples for Electron Microscope Studies

1974 ◽  
Vol 32 ◽  
pp. 548-549
Author(s):  
T. J. Magee ◽  
J. Peng ◽  
J. Bean
Keyword(s):  
Electron Microscope ◽  
Sulfuric Acid ◽  
Solid State ◽  
Sample Preparation ◽  
Cadmium Telluride ◽  
Potassium Dichromate ◽  
Optical Components ◽  
The Past ◽  
Solid State Devices

Cadmium telluride has become increasingly important in a number of technological applications, particularly in the area of laser-optical components and solid state devices, Microstructural characterizations of the material have in the past been somewhat limited because of the lack of suitable sample preparation and thinning techniques. Utilizing a modified jet thinning apparatus and a potassium dichromate-sulfuric acid thinning solution, a procedure has now been developed for obtaining thin contamination-free samples for TEM examination.

The influence of potassium dichromate on dissimilatory reduction of sulfate and nitrate ions by bacteria Desulfovibrio sp.

2017 ◽  
Vol 28 (1-2) ◽  
pp. 84-95
Author(s):  
O. M. Moroz ◽  
S. O. Hnatush ◽  
Ch. I. Bohoslavets ◽  
T. M. Hrytsun’ ◽  
B. M. Borsukevych
Keyword(s):  
Electron Acceptor ◽  
Potassium Dichromate ◽  
Anaerobic Respiration ◽  
Sulfate Reducing Bacteria ◽  
Negative Influence ◽  
Electron Acceptors ◽  
Metal Compounds ◽  
Nitrate Ions ◽  
Sulfate Reducing ◽  
Reducing Bacteria

Sulfate reducing bacteria, capable to reductive transformation of different nature pollutants, used in biotechnologies of purification of sewage, contaminated by carbon, sulfur, nitrogen and metal compounds. H2S formed by them sediment metals to form of insoluble sulfides. Number of metals can be used by these microorganisms as electron acceptors during anaerobic respiration. Because under the influence of metal compounds observed slowing of bacteria metabolism, selection isolated from technologically modified ecotops resistant to pollutions strains is important task to create a new biotechnologies of purification. That’s why the purpose of this work was to study the influence of potassium dichromate, present in medium, on reduction of sulfate and nitrate ions by sulfate reducing bacteria Desulfovibrio desulfuricans IMV K-6, Desulfovibrio sp. Yav-6 and Desulfovibrio sp. Yav-8, isolated from Yavorivske Lake, to estimate the efficiency of possible usage of these bacteria in technologies of complex purification of environment from dangerous pollutants. Bacteria were cultivated in modified Kravtsov-Sorokin medium without SO42- and FeCl2×4H2O for 10 days. To study the influence of K2Cr2O7 on usage by bacteria SO42- or NO3- cells were seeded to media with Na2SO4×10H2O or NaNO3 and K2Cr2O7 at concentrations of 1.74 mM for total content of electron acceptors in medium 3.47 mM (concentration of SO42- in medium of standard composition). Cells were also seeded to media with 3.47 mM Na2SO4×10H2O, NaNO3 or K2Cr2O7 to investigate their growth in media with SO42-, NO3- or Cr2O72- as sole electron acceptor (control). Biomass was determined by turbidymetric method, content of sulfate, nitrate, dichromate, chromium (III) ions, hydrogen sulfide or ammonia ions in cultural liquid – by spectrophotometric method. It was found that K2Cr2O7 inhibits growth (2.2 and 1.3 times) and level of reduction by bacteria sulfate or nitrate ions (4.2 and 3.0 times, respectively) at simultaneous addition into cultivation medium of 1.74 mM SO42- or NO3- and 1.74 mM Cr2O72-, compared with growth and level of reduction of sulfate or nitrate ions in medium only with SO42- or NO3- as sole electron acceptor. Revealed that during cultivation of bacteria in presence of equimolar amount of SO42- or NO3- and Cr2O72-, last used by bacteria faster, content of Cr3+ during whole period of bacteria cultivation exceeded content H2S or NH4+. K2Cr2O7 in medium has most negative influence on dissimilatory reduction by bacteria SO42- than NO3-, since level of nitrate ions reduction by cells in medium with NO3- and Cr2O72- was a half times higher than level of sulfate ions reduction by it in medium with SO42- and Cr2O72-. The ability of bacteria Desulfovibrio sp. to priority reduction of Cr2O72- and after their exhaustion − NO3- and SO42- in the processes of anaerobic respiration can be used in technologies of complex purification of environment from toxic compounds.

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