Qualitative Detection of Titanium Dioxide in Rubber

1949 ◽  
Vol 22 (1) ◽  
pp. 286-286 ◽  
Author(s):  
G. L. Hammond
Keyword(s):  
Titanium Dioxide ◽  
Sulfuric Acid ◽  
Chromotropic Acid ◽  
Disulfonic Acid ◽  
Qualitative Detection ◽  
Yellow Color ◽  
Golden Yellow ◽  
Porcelain Crucible ◽  
Purple Coloration ◽  
Concentrated Sulfuric Acid

Abstract Titanium dioxide, either as such or in the form of the composite titanium whites, is now used to such an extent as a rubber pigment that a test for titanium is frequently necessary in the analysis of a compounded rubber. Owing to the insoluble nature of titanium dioxide, troublesome fusions are required to detect it by the normal qualitative tests in the ash remaining when a rubber is incinerated. The following method is offered as a quick and easy means of detecting titanium. A small portion (about 0.01 gram usually suffices) of the ash from the sample is placed in a clean glazed 15-cc. Porcelain crucible. One drop of concentrated sulfuric acid is then added, and the whole is heated on a hot plate for 30 seconds, i.e., until most of the acid is evaporated. The crucible is allowed to cool, and 2 drops of 6 N sulfuric acid added, followed by 1 drop of a 5 per cent aqueous solution of the sodium salt of chromotropic acid (1,8-dihydroxynaphthalene-3,6-disulfonic acid). A brownish red to purple coloration is obtained if titanium be present. In place of the chromotropic acid, 1 drop of 10-volume hydrogen peroxide is added in a second test, when the well-known golden yellow color is obtained.

Meso and β-pyrrole sulfonated porphyrins obtained by sulfonation of 5,15-bis(phenyl)porphyrin

2000 ◽  
Vol 04 (05) ◽  
pp. 564-568 ◽  
Author(s):  
HECTOR GARCIA-ORTEGA ◽  
JOSEP M. RIBO
Keyword(s):  
Sulfuric Acid ◽  
Sodium Salt ◽  
Good Yield ◽  
Sulfonic Acid ◽  
Disulfonic Acid ◽  
Acid Mixture ◽  
Sodium Salts ◽  
Concentrated Sulfuric Acid ◽  
Trisodium Salt

The sulfonation of 5,15-bis(phenyl)porphyrin (DPP) in concentrated sulfuric acid results in substitution on the β-pyrrolic positions and the expected sulfonation on the para positions of the phenyl substituents. The sodium salt of 5,15-bis(4-sulfonatophenyl)porphyrin-2-sulfonic acid ( S 3 DPP ) was prepared in good yield, the sodium salts of 5,15-bis(4-sulfonatophenyl)porphyrin ( S 2 A DPP ), 5-phenyl-15-(4-sulfonatophenyl)porphyrin-2-sulfonic acid ( S 2 B DPP ) and 15-phenyl-5-(4-sulfonatophenyl)porphyrin ( S 1 A DPP ) were isolated, and 5,15-bis(phenyl)porphyrin-2-sulfonic acid ( S 1 B DPP ) was detected in a mixture with S 1 A DPP . The β-pyrrole sulfonato substituents are stable and their potential synthetic use is shown by the preparation of the trisodium salt of 10-bromo-5,15-bis(4-sulfonatophenyl)porphyrin-2-sulfonic acid ( BrS 3 DPP ) by NBS bromination of S 3 DPP . In a methanol/sulfuric acid mixture the sulfonation occurs on the meso positions, and the tetrasodium salt of 10,20-bis (4-sulfonatophenyl)porphyrin-5,15-disulfonic acid ( S 4 DPP ) was obtained.

Extraction and GLC Detection of Pentachlorophenol and 2,3,4,6-Tetrachlorophenol in Fats, Oils, and Fatty Acids

1970 ◽  
Vol 53 (4) ◽  
pp. 673-676
Author(s):  
G R Higginbotham ◽  
John Ress ◽  
Alan Rocke
Keyword(s):  
Fatty Acids ◽  
Sulfuric Acid ◽  
Petroleum Ether ◽  
Electron Capture ◽  
Tentative Method ◽  
Food Grade ◽  
Qualitative Detection ◽  
Wide Range ◽  
Concentrated Sulfuric Acid ◽  
Ppm Level

Abstract A proposed tentative method for detection of residues of pentachlorophenol and 2,3,4,6-tetrachlorophenol in fats, oils, and commercial food grade fatty acids consists of treating a 5.0 g sample with concentrated sulfuric acid and Celite, followed by a series of liquid-liquid extractions with petroleum ether, aqueous alkali, and chloroform. The residue from the final extract, after further treatment with concentrated sulfuric acid, is analyzed by electron capture GLC. Recoveries of the 2 volatile polychlorophenols were low and varied over a wide range; however, the tentative procedure appears to be satisfactory for qualitative detection at the 0.5 ppm level. Several samples of commercial oleic acids contaminated with chick edema factors were analyzed and were found to be contaminated with pentachlorophenol. Further study of the method is recommended.

Investigate of the Ability of Cronobacter sakazakii Isolated from Clinical Samples of Children Under Two Years to Induce Swimming, Swarming and Biofilm

2018 ◽  
pp. 123
Author(s):  
Luma Abdal Hady Zwein ◽  
Tharieyt Abdulrahman Motlag ◽  
Mohamed Mousa
Keyword(s):  
Cerebrospinal Fluid ◽  
Congo Red ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Clinical Samples ◽  
Cronobacter Sakazakii ◽  
Yellow Color ◽  
Golden Yellow ◽  
Vitek 2 ◽  
Biochemical Examination

      The study included 200 samples were collected   from   children  under two   years included (50 samples from each of Cerebrospinal fluid, Blood, Stool and Urine) from, Central Children Hospital and Children's Protections Educational Hospital. Isolates bacterial were obtained cultural, microscopic and biochemical examination and diagnosed to the species by using vitek2 system. The results showed there were contamination in 6.5% of clinical samples. The diagnosed colonies which gave pink color on the MacConkey agar , golden yellow color on the Trypton Soy agar and green color on the Birillent Enterobacter sakazakii agar and gave  a probability of 99% in the vitek 2 and were identified as Cronobacter sakazakii. The identification revealed of thirteen isolates: 6(46.16%) isolated from Cerebrospinal fluid samples, 7(53.84%) isolated from blood samples and not isolated bacteria from stool and urine samples. The results of the investigation of some virulence factors showed that all bacteria isolates were able to swimming with a diameter ranging (1-9 mm) and swarming with a diameter ranging (1-40 mm) and their  ability to biofilm formation  by using three methods. The results show the ability  of  isolates to form biofilm by using  Congo red media  methods where it is 12 (92.30 %) out of 13 isolated bacteria belonging to C. sakazakii  able to form biofilm on the Congo red media  which is 3 (23.07%) were  strong production  biofilm ,   8 (61.53%)  were intermediate  production  biofilm and  1 (7.69% ) were weak  biofilm formation , while the 1 (7.69%)  unable to form biofilm.  Tubes method were all isolates were able to form biofilm, it were found that 3 (23.07%)  isolates strong, and 8 (61.53%) intermediate  and 2( 15.38%)  weak biofilm formation. Microtiter plate method  gave 5 (38.46 %) isolates strong, 6 (46.15%) intermediate and 1 (7.69%) weak biofilm formation.  

Gallium Arsenide Integrated Circuits Decapsulation Technique Using Mixed Acid Chemistry For Die-Level Failure Analysis

2018 ◽  
Author(s):  
Harold Jeffrey M. Consigo ◽  
Ricardo S. Calanog ◽  
Melissa O. Caseria
Keyword(s):  
Gallium Arsenide ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
Mixed Acid ◽  
Optimum Parameters ◽  
Plastic Package ◽  
Fuming Nitric Acid ◽  
Concentrated Sulfuric Acid

Abstract Gallium Arsenide (GaAs) integrated circuits have become popular these days with superior speed/power products that permit the development of systems that otherwise would have made it impossible or impractical to construct using silicon semiconductors. However, failure analysis remains to be very challenging as GaAs material is easily dissolved when it is reacted with fuming nitric acid used during standard decapsulation process. By utilizing enhanced chemical decapsulation technique with mixture of fuming nitric acid and concentrated sulfuric acid at a low temperature backed with statistical analysis, successful plastic package decapsulation happens to be reproducible mainly for die level failure analysis purposes. The paper aims to develop a chemical decapsulation process with optimum parameters needed to successfully decapsulate plastic molded GaAs integrated circuits for die level failure analysis.

PRODUCTION OF SULFOCATIONITE BY MODIFICATION OF NATURAL COAL WITH CONCENTRATED SULFURIC ACID

2020 ◽  
Vol 3 (441) ◽  
pp. 104-109
Author(s):  
N.A. Bektenov ◽  
◽  
N.C. Murzakassymova ◽  
M.A. Gavrilenko ◽  
А.N. Nurlybayeva ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Concentrated Sulfuric Acid ◽  
Natural Coal

Addition of primary alcohols to 3-chlorononafluoro-1,5-hexadiene and perfluoro-1,3,5-hexatriene

1985 ◽  
Vol 50 (8) ◽  
pp. 1714-1726 ◽  
Author(s):  
Václav Dědek ◽  
Igor Linhart ◽  
Milan Kováč
Keyword(s):  
Sulfuric Acid ◽  
Primary Alcohols ◽  
Principal Product ◽  
Allyl Rearrangement ◽  
Concentrated Sulfuric Acid ◽  
Sodium Alkoxide

Sodium alkoxide-catalyzed addition of methanol, ethanol and propanol to 3-chlorononafluoro-1,5-hexadiene (I) proceeds at temperatures -35 °C to 8 °C with allyl rearrangement, affording 1,6-dialkoxy-1,1,2,3,4,4,5,6,6-octafluoro-2,4-hexadiene (V) as the principal product, along with 1,6-dialkoxy-1,2,3,3,4,5,6,6-octafluoro-1,5-diene (VI) and trans-1,6-dialkoxy-1,1,2,3,4,4,5,6,6-nonafluoro-2-hexene (VII). The ethers Va-Vc consist of the cis,trans- and trans,trans-isomers in about 3 : 1 ratio, whereas the ethers VIa-VIc have trans,trans-configuration. Ethers Vc and VIc react with concentrated sulfuric acid to give dipropyl 2,3,4,5-tetrafluoro-2,4-hexadienedioate (IX) and dipropyl 2,3,4,4,5-pentafluoro-2-hexenedioate (X), respectively, whereas the ether VIIc affords a mixture of propyl 6-propyloxy-2,3,4,4,5,6-heptafluoro-2-hexenoate (XI) and ester X. Addition of methanol to perfluoro-1,3,5-hexatriene (II) affords 1,1,2,3,4,5,6,6-octafluoro-1,6-dimethoxy-3-hexene (XIII) as the principal product.

scholarly journals 4,5,6-Trichloropyrimidine-2-carboxamide

Molbank ◽  
10.3390/m1190 ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. M1190
Author(s):  
Andreas S. Kalogirou ◽  
Panayiotis A. Koutentis
Keyword(s):  
Sulfuric Acid ◽  
Elemental Analysis ◽  
Maldi Tof ◽  
Concentrated Sulfuric Acid

Reaction of 4,5,6-trichloropyrimidine-2-carbonitrile (1) with concentrated sulfuric acid at ca. 20 °C gave 4,5,6-trichloropyrimidine-2-carboxamide (5) in 91% yield. The new compound was fully characterized by IR, MALDI-TOF, NMR and elemental analysis.

Regioselective Bromination of Anilines in the Presence of Nitrosonium Hydrogensulfate in Concentrated Sulfuric Acid

1995 ◽  
Vol 5 (2) ◽  
pp. 65-66 ◽  
Author(s):  
Mikhail V. Gorelik ◽  
Vera I. Lomzakova ◽  
Elena A. Khamidova ◽  
Vitalii Ya. Shteiman ◽  
Marianna G. Kuznetsova ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Concentrated Sulfuric Acid
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