Absorptiometric Microdetermination of Total Sulfur in Rubber Products

Abstract The 1.0 to 2.5 per cent of sulfur normally present in rubber products is oxidized with concentrated nitric acid-bromine reagent, followed by perchloric acid in the presence of excess lead nitrate. Sulfur as lead sulfate is precipitated and washed with acetone. The lead sulfate is dissolved in 50 per cent hydrochloric acid, and absorbance of the lead chloride complex is recorded at 270 mµ. Sulfur is calculated on the basis of the measured lead content of the precipitate. The high sensitivity puts the method in the micro-range. An experienced analyst can analyze 40 to 50 samples a day. Precision and accuracy are comparable to those of the conventional barium sulfate gravimetric method at the low sulfur concentrations normally found in rubber products.

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A Single LC-MS/MS Analysis to Quantify CoA Biosynthetic Intermediates and Short-Chain Acyl CoAs

Metabolites ◽

10.3390/metabo11080468 ◽

2021 ◽

Vol 11 (8) ◽

pp. 468

Author(s):

Anthony E. Jones ◽

Nataly J. Arias ◽

Aracely Acevedo ◽

Srinivasa T. Reddy ◽

Ajit S. Divakaruni ◽

...

Keyword(s):

Mass Spectrometry ◽

Sample Preparation ◽

Biosynthetic Pathway ◽

Solid Phase ◽

High Sensitivity ◽

Short Chain ◽

Extraction Column ◽

Chain Acyl ◽

Precision And Accuracy ◽

Mass Spectrometry Mass Spectrometry

Coenzyme A (CoA) is an essential cofactor for dozens of reactions in intermediary metabolism. Dysregulation of CoA synthesis or acyl CoA metabolism can result in metabolic or neurodegenerative disease. Although several methods use liquid chromatography coupled with mass spectrometry/mass spectrometry (LC-MS/MS) to quantify acyl CoA levels in biological samples, few allow for simultaneous measurement of intermediates in the CoA biosynthetic pathway. Here we describe a simple sample preparation and LC-MS/MS method that can measure both short-chain acyl CoAs and biosynthetic precursors of CoA. The method does not require use of a solid phase extraction column during sample preparation and exhibits high sensitivity, precision, and accuracy. It reproduces expected changes from known effectors of cellular CoA homeostasis and helps clarify the mechanism by which excess concentrations of etomoxir reduce intracellular CoA levels.

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Sedimentation Volume of Sparingly Soluble Salts. V-VI. V. The Effects of Common Ions on the Sedimentation Volume of Barium Sulfate, Barium Chromate, Lead Sulfate and Lead Chromate

Nippon kagaku zassi ◽

10.1246/nikkashi1948.81.2_236 ◽

1960 ◽

Vol 81 (2) ◽

pp. 236-239

Author(s):

Tetsuo MORIMOTO

Keyword(s):

Barium Sulfate ◽

Lead Sulfate ◽

Lead Chromate ◽

Soluble Salts ◽

Barium Chromate ◽

Sedimentation Volume

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Formation and Application of High Reflectivity Controllable Barium Sulfate Microspheres

Crystals ◽

10.3390/cryst8090333 ◽

2018 ◽

Vol 8 (9) ◽

pp. 333 ◽

Cited By ~ 1

Author(s):

Yuejiao Liu ◽

Xiaoyan Guo ◽

Qingyang Gu ◽

Guangxiang He ◽

Suohe Yang ◽

...

Keyword(s):

Barium Sulfate ◽

Ethylenediaminetetraacetic Acid ◽

Density Lipoprotein ◽

High Sensitivity ◽

Particle Morphology ◽

Disodium Edta ◽

Reaction Conditions ◽

X Ray ◽

High Reflectivity ◽

Good Repeatability

This paper investigated the influence of reaction conditions on particle morphology. X-ray powder diffraction (XRD), particle size distribution (PSD), and scanning electron microscopy (SEM) were used to characterize the morphology of barium sulfate. The barium sulfate microspheres were synthesized with BaCl2, Na2SO4, and ethylenediaminetetraacetic acid disodium (EDTA·2Na). The reflectivity of the synthesized barium sulfate microspheres was greater than 99% in the range of 400–700 nm, which was characterized by a reflectance spectrometer. The morphology of the barium sulfate particles and their cross-section were observed by SEM. The prepared microspheres were applied to high-density lipoprotein dry tablets due to their high reflectivity, and the results showed that the prepared tablets had high sensitivity and good repeatability.

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Volumetric Determination of Sulfate by Titration of Excess Lead Nitrate with Potassium Chromate Using Siloxene Indicator

Analytical Chemistry ◽

10.1021/ac50162a036 ◽

1957 ◽

Vol 29 (4) ◽

pp. 543-546 ◽

Cited By ~ 13

Author(s):

Frederic. Kenny ◽

R. B. Kurtz ◽

Inge. Beck ◽

Irena. Lukosevicius

Keyword(s):

Lead Nitrate ◽

Potassium Chromate ◽

Excess Lead ◽

Volumetric Determination

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High-Sensitivity High-Resolution Full-Wafer Imaging of the Properties of Large n-Type SiC Using the Relative Reflectance of Two Terahertz Waves

Materials Science Forum ◽

10.4028/www.scientific.net/msf.778-780.491 ◽

2014 ◽

Vol 778-780 ◽

pp. 491-494 ◽

Cited By ~ 2

Author(s):

Akihide Hamano ◽

Seigo Ohno ◽

Hiroaki Minamide ◽

Hiromasa Ito ◽

Yoshiyuki Usuki

Keyword(s):

Silicon Carbide ◽

Relaxation Time ◽

Carrier Density ◽

High Sensitivity ◽

Thz Imaging ◽

Terahertz Waves ◽

Large N ◽

Imaging Results ◽

Standard Values ◽

Precision And Accuracy

THz imaging was performed in 2 s intervals with 1 mm resolution on a 3 in., 0.42 mm thick, as-cut n-type Silicon Carbide wafer. Carrier density, relaxation time, mobility, and resistivity obtained from imaging results are 0.91 × 1018 cm-3, 4.36 × 10-14 s, 218 cm2V-1s-1, and 3.14 × 10-2 Ωcm, respectively. Compared with the standard values provided by the manufacturers, the results suggest that THz imaging has reliable precision and accuracy.

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Advantages of glutamate dehydrogenase as a blood biomarker of acute hepatic injury in rats

Laboratory Animals ◽

10.1258/002367702320162414 ◽

2002 ◽

Vol 36 (3) ◽

pp. 313-321 ◽

Cited By ~ 107

Author(s):

P. J. O'Brien ◽

M. R. Slaughter ◽

S. R. Polley ◽

K. Kramer

Keyword(s):

Glutamate Dehydrogenase ◽

Partial Hepatectomy ◽

Tissue Specificity ◽

Hepatic Injury ◽

Lead Nitrate ◽

High Sensitivity ◽

Hepatic Necrosis ◽

Hepatocellular Injury ◽

Blood Biomarker ◽

Acute Hepatic Injury

In a recent study in rats, alanine aminotransferase (ALT), the preferred plasma biomarker of hepatocellular injury in rats, was ineffective at detecting marked hepatic necrosis produced by acetaminophen ( Human and Experimental Toxicology 19, 277-83, 2000). In contrast, glutamate dehydrogenase (GLDH) was markedly elevated. Accordingly, these enzymes were comprehensively evaluated as plasma biomarkers of hepatocellular injury in rats using several other models of hepatic injury, including partial hepatectomy and exposure to methapyrilene, dexamethasone, cyproterone, isoniazid, lead nitrate, and Wyeth-14643. Other enzymes also evaluated were aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH), and the hepatobiliary marker alkaline phosphatase (ALP). Compared to plasma ALT increases, plasma GLDH increases were up to 10-fold greater, up to 3-fold more persistent, and occurred at times following hepatocellular injury when plasma ALT was not increased. Plasma GLDH activity was not inhibited by the test compounds, whereas ALT was substantially inhibited by both isoniazid and lead nitrate. While plasma GLDH activity was unaffected by induction, ALT was induced by cyproterone and dexamethasone, and ALP was induced by Wyeth-14643 and partial hepatectomy. GLDH was concluded to be a more effective biomarker of acute hepatic injury than ALT, AST, SDH or ALP in the rat, based primarily on the large increase following hepatocellular injury, prolonged persistence in the blood following injury, high sensitivity for detection of injury (including pre-necrotic injury), high tissue specificity, and lower susceptibility to inhibition or induction.

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The growth of metal excess lead chloride from the vapour phase

Australian Journal of Chemistry ◽

10.1071/ch9641188 ◽

1964 ◽

Vol 17 (10) ◽

pp. 1188 ◽

Cited By ~ 3

Author(s):

AL Walker ◽

AS Buchanan

Keyword(s):

Vapour Phase ◽

Lead Chloride ◽

Excess Lead

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Measurement of Ultra Low Sulfur in IN718 by Using Infrared Absorption Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.989-994.115 ◽

2014 ◽

Vol 989-994 ◽

pp. 115-120

Author(s):

P.R. Zalupski ◽

Feng Yan Liu

Keyword(s):

Experimental Data ◽

Infrared Absorption ◽

Absorption Method ◽

Feasible Method ◽

Experimental Process ◽

Precision And Accuracy ◽

Low Sulfur

The paper introduces an experimental process on measurement of ultra low sulfur in IN718 by using infrared carbon sulfur analyzer. The experimental data shows that, infrared absorption method can be used to analyze and measure the ultra low sulfur in IN718, and the precision and accuracy of this method meets the requirement of ASTM E l019-2000. It can be concluded that it is a feasible method in practice.

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