Vulcanization Chemistry. Sulfur, Nt-Butyl-2-Benzothiazole Sulfenamide Formulations Studied by High Performance Liquid Chromatography

1992 ◽  
Vol 65 (2) ◽  
pp. 488-501 ◽  
Author(s):  
A. B. Sullivan ◽  
Cynthia J. Hann ◽  
George H. Kuhls
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Material Balance ◽  
Side Reaction ◽  
Analytical Methodology ◽  
Wide Range ◽  
Kinetics Of ◽  
Vulcanization Process ◽  
Intermediate Concentration

Abstract The paper reports on the sulfur vulcanization chemistry of cis-polyisoprene formulations accelerated with N-t-butyl-2-benzothiazole sulfenamide. High Performance Liquid Chromatography (HPLC) is utilized to examine the kinetics of accelerator—sulfur disappearance and the formation—disappearance profiles of extra-network cure intermediates across the vulcanization process. Cure profile measurements are reported on three formulations covering a wide range of sulfur—accelerator ratios. Also unique aspects of the analytical methodology are highlighted. The observed cure-intermediate concentration profiles reinforce earlier theories about the chemical details of sulfurization and subsequent crosslinking. On all formulations, benzothiazole polysulfides (S1−S4) reach a maximum concentration at the scorch midpoint coincident with slope changes in reactant and product profiles. Although pendant-accelerator crosslink precursors are not measured directly, their presence is implied from material balance calculations. Also, the formation of a small amount of benzothiazole early in the scorch period is a new observation in sulfenamide acceleration. It suggests that accelerator hydrolysis is a competitive side reaction early in the vulcanization process.

scholarly journals High-performance liquid chromatography-based method to evaluate kinetics of glucosinolate hydrolysis by Sinapis alba myrosinase

2014 ◽  
Vol 465 ◽  
pp. 105-113 ◽  
Author(s):  
Kayla J. Vastenhout ◽  
Ruthellen H. Tornberg ◽  
Amanda L. Johnson ◽  
Michael W. Amolins ◽  
Jared R. Mays
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Sinapis Alba ◽  
Kinetics Of

scholarly journals Chemical Constituents of Snake Fruit (Salacca zalacca (Gaert.) Voss) Peel and in silico Anti-aging Analysis

2019 ◽  
Vol 3 (2) ◽  
pp. 122
Author(s):  
Ermi Girsang ◽  
I Nyoman Ehrich Lister ◽  
Chrismis Novalinda Ginting ◽  
Adrian Khu ◽  
Butter Samin ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Chlorogenic Acid ◽  
High Performance ◽  
Biological Activities ◽  
Chemical Constituents ◽  
Palm Tree ◽  
Triterpenoid Saponin ◽  
Fruit Peel ◽  
Wide Range

Background: Skin aging is a condition where skin is unable to retain both its physiological and structural integrity. Plants is the main source of phtytochemicals compound with wide range of biological activities. Through the efforts of ongoing scientific researches, an increasing number of plant extracts and phytochemicals have been showed promising result as anti-aging agent. Snake fruit (Salacca zalacca (Gaert.) Voss) is tropical plant belongs to the palm tree family (Arecaceae) that served as important crop in Indonesia. Despite its utilization, the phytochemical compound available in snake fruit, especially its peel have not been well documented. Present study aimed to elucidate the phytochemical constituent of snake fruit peel and its anti-aging potency.Materials and Methods: Snake fruit peel extract (SPE) was subjected to qualitative phytochemical assay, high performance liquid chromatography, and molecular docking towards protein related in skin aging.Results: The screening showed SPE contained phytochemical compound belong to flavonoid, tannin, phenol, triterpenoid, saponin and alkaloid. Thus, based on the analysis only chlorogenic acid was present in SPE whilst rutin and caffeic acid were not detected. The SPE was contained chlorogenic acid around 1.074 mg/g dry weight. Chlorogenic acid had the high binding affinity towards matrix metalloproteinase (MMP)-1 (-9.4 kcal/mol).Conclusion: Current findings may provide scientific evidence for possible usage of SPE and its compounds as antioxidant and anti-aging agent.Keywords: Salacca zalacca, phytochemical compound, high performance liquid chromatography, anti-aging

Ceftazidime kinetics of diffusion in inoculated agar plates.

1996 ◽  
Vol 40 (5) ◽  
pp. 1280-1281 ◽  
Author(s):  
C Arcelloni ◽  
R Paroni ◽  
M Basile ◽  
P A Bonini ◽  
R Vaiani
Keyword(s):  
Pseudomonas Aeruginosa ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Fixed Points ◽  
High Performance ◽  
Statistical Difference ◽  
Disk Center ◽  
Beta Lactamase ◽  
Fixed Times ◽  
Kinetics Of

The ceftazidime concentration in agar plates inoculated with Pseudomonas aeruginosa was determined by high-performance liquid chromatography at fixed points (3, 6, 9, 12, and 15 mm) from the disk center and at fixed times (2, 4, 6, 16, and 24 h) to study the antibiotic kinetics of diffusion. A statistical difference between the concentrations determined in the presence of microorganisms and in uninoculated plates after 16 and 24 h was evidenced and was probably ascribable to the drug hydrolysis carried out by the induced beta-lactamase.

Determination of Aflatoxins, Ochratoxin A, and Zearalenone in Mixed Feeds, with Detection by Thin Layer Chromatography or High Performance Liquid Chromatography

1981 ◽  
Vol 64 (6) ◽  
pp. 1356-1363 ◽  
Author(s):  
Mary V Howell ◽  
Philip W Taylor
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Wide Range ◽  
Mixed Feeds ◽  
Layer Chromatography

Abstract A sensitive, reliable, and economical method for the determination of 6 mycotoxins in mixed feeds is described. The feed is extracted with chloroform-water and the extract is cleaned up by using a disposable Sep-Pak silica cartridge. The procedure requires less time (15 min from sample extraction to extract preparation) and less solvent (approximately one-tenth) compared with conventional methods and is suitable for a fast, economical screen. Additional cleanup procedures, involving dialysis or extraction into base, are described for samples containing high levels of interfering compounds. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with fluorescence detection are described for identification and estimation of mycotoxins. The method has been applied to a wide range of mixed feeds, including laboratory animal diets, and raw materials. The limit of detection is 1 μg/kg for all mycotoxins measured by HPLC.

Free and hidden fumonisins in Argentinean raw maize samples

2020 ◽  
Vol 13 (1) ◽  
pp. 109-116
Author(s):  
P.S. Pok ◽  
V.A. García Londoño ◽  
S.P. Aransibia ◽  
S. Vicente ◽  
A.M. Pacín ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
European Commission ◽  
Alkaline Hydrolysis ◽  
High Performance ◽  
Fluorescence Detector ◽  
Analytical Methodology ◽  
Limits Of Detection

The concentrations of free fumonisins (FBs) and hydrolysed fumonisins (HFBs) were determined in 72 maize samples collected in 2017 from five Argentine provinces. The methodology for HFBs analysis consisted of alkaline hydrolysis followed by high performance liquid chromatography with a fluorescence detector (HPLC-FLD). The developed analytical methodology presented percentages of recovery greater than 74%. Limits of detection were 4.5, 13.0 and 12.9 μg/kg for HFB1, HFB2 and HFB3, respectively. Presence of FBs was found in 86% of the samples. In all cases, the concentration of total HFBs (after the hydrolysis treatment) was superior to the free FBs content (HFBs to FBs median ratio of 2.5), which indicates the presence of hidden fumonisins in Argentinean maize. 8% of the traditionally analysed samples exceeded the limit established by the European Commission for FB1 + FB2. When applying alkaline hydrolysis to the samples, 24% of them exceed this limit.

Sign in / Sign up

Export Citation Format

Share Document