Near-electrode pH change for voltammetric detection of insoluble lead carbonate

2021 ◽  
Vol 1186 ◽  
pp. 339087
Author(s):  
Artur Huseinov ◽  
Benjamin L. Weese ◽  
Brody J. Brewer ◽  
Noe T. Alvarez
Keyword(s):  
Ph Change ◽  
Lead Carbonate ◽  
Voltammetric Detection

Effect of pH and NH4NO3 as a Spray Additive on Penetration of NAA Through Isolated Tomato Fruit Cuticle

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 550a-550 ◽  
Author(s):  
Royal G. Fader ◽  
Martin J. Bukovac
Keyword(s):  
Direct Measurement ◽  
Sodium Citrate ◽  
Tomato Fruit ◽  
Initial Slope ◽  
Control Effect ◽  
Solution Ph ◽  
Ph Change ◽  
Effect Of Ph ◽  
Spray Droplets ◽  
Partition Behavior

We have reported that NH4NO3 (AN, 8 mM, pH 4.2), applied as simulated spray droplets, enhanced penetration of 14C-NAA through isolated leaf and fruit cuticles. One explanation for this response is that AN depresses NAA (pKa= 4.2) dissociation, increasing the nondissociated moiety, which penetrates more readily than the anion (NAA'). Direct measurement of AN (concn. 0-800 mM) effect on NAA (215 μM) dissociation as indexed by change in solution pH revealed no significant effect, with a pH change from 4.19 to 4.05. This change is not sufficient to account for the observed enhancement. When 14C-NAA, buffered (20 mM sodium citrate) at pH 3.2, 4.2, 5.2, 6.2, was partitioned against chloroform, there was a marked increase in NAA partitioning into chloroform as pH was decreased. AN (8 mM) did not alter this partition behavior, also indicating no effect on NAA dissociation. However, in cuticle penetration studies, using a finite dose system with 14C-NAA buffered at pH 3.2, 4.2, 5.2, 6.2, and in the presence and absence of 8 mM AN, there was no marked or consistent pH or AN (-70 to + 232 % of no AN control) effect on penetration as indexed by initial slope (4-12 h) or penetration after 120 h. The possible effects of AN and buffer on penetration of 14C-NAA from the droplet deposit will be discussed.

Voltammetric Detection of Tetrodotoxin Real-Time In Vivo of Mouse Organs using DNA-Immobilized Carbon Nanotube Sensors

2019 ◽  
Vol 15 (5) ◽  
pp. 567-574
Author(s):  
Huck Jun Hong ◽  
Suw Young Ly
Keyword(s):  
Carbon Nanotube ◽  
Real Time ◽  
Anticancer Agents ◽  
Cancer Metastasis ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Takifugu Rubripes ◽  
In Vivo Detection ◽  
Voltammetric Detection

Background: Tetrodotoxin (TTX) is a biosynthesized neurotoxin that exhibits powerful anticancer and analgesic abilities by inhibiting voltage-gated sodium channels that are crucial for cancer metastasis and pain delivery. However, for the toxin’s future medical applications to come true, accurate, inexpensive, and real-time in vivo detection of TTX remains as a fundamental step. Methods: In this study, highly purified TTX extracted from organs of Takifugu rubripes was injected and detected in vivo of mouse organs (liver, heart, and intestines) using Cyclic Voltammetry (CV) and Square Wave Anodic Stripping Voltammetry (SWASV) for the first time. In vivo detection of TTX was performed with auxiliary, reference, and working herring sperm DNA-immobilized carbon nanotube sensor systems. Results: DNA-immobilization and optimization of amplitude (V), stripping time (sec), increment (mV), and frequency (Hz) parameters for utilized sensors amplified detected peak currents, while highly sensitive in vivo detection limits, 3.43 µg L-1 for CV and 1.21 µg L-1 for SWASV, were attained. Developed sensors herein were confirmed to be more sensitive and selective than conventional graphite rodelectrodes modified likewise. A linear relationship was observed between injected TTX concentration and anodic spike peak height. Microscopic examination displayed coagulation and abnormalities in mouse organs, confirming the powerful neurotoxicity of extracted TTX. Conclusion: These results established the diagnostic measures for TTX detection regarding in vivo application of neurotoxin-deviated anticancer agents and analgesics, as well as TTX from food poisoning and environmental contamination.

Correction: Evaluation of Root pH Change Through Gel Containing pH-sensitive Indicator Bromocresol Purple

BIO-PROTOCOL ◽  
2018 ◽  
Vol 8 (8) ◽  
Author(s):  
Aparecida Silva ◽  
Keini Dressano ◽  
Paulo Ceciliato ◽  
Juan Carlos Guerrero-Abad ◽  
Daniel Moura
Keyword(s):  
Ph Sensitive ◽  
Sensitive Indicator ◽  
Bromocresol Purple ◽  
Ph Change

scholarly journals Electrochemical treatment of ex vivo human abdominal skin and potential use in scar management: A pilot study

2021 ◽  
Vol 7 ◽  
pp. 205951312098853
Author(s):  
Dana M Hutchison ◽  
Amir A Hakimi ◽  
Avin Wijayaweera ◽  
Soohong Seo ◽  
Ellen M Hong ◽  
...  
Keyword(s):  
Color Change ◽  
Ex Vivo ◽  
Low Cost ◽  
Histological Evaluation ◽  
Ph Change ◽  
Level Of Evidence ◽  
Abdominal Skin ◽  
Electrochemical Therapy ◽  
Mean Width ◽  
Scar Management

Introduction: Scar treatments aim to address pathologic collagen deposition; however, they can be expensive or difficult to control. Electrochemical therapy (ECT) offers a simple alternative treatment. The purpose of this study is to examine the acid-base and histological changes in ex vivo human abdominal skin following ECT. Methods: Forty-two ex vivo human panniculus tissue sections collected from six individuals were tumesced with normal saline. ECT was performed by inserting two platinum needle electrodes connected to a DC power supply into each specimen. Voltage was varied (3–6 V) and applied for 5 minutes. Each specimen was sectioned across both electrode insertion sites and immediately stained with pH sensitive dye. The width of dye color change for each dosimetry pair was calculated. Hematoxylin and eosin staining was used to evaluate samples. Results and Discussion: ECT caused a spatially localised and dose-dependent increased area of acidic and basic pH around the anode and cathode, respectively. A significantly greater mean width of pH change was generated at the cathode compared to the anode in all treatment groups. Histological evaluation displayed broad condensation and hyalinisation of dermal collagen. Conclusion: ECT triggered dermal pH alterations and changed the underlying structural framework of the specimen. This technology may serve as a low-cost, minimally invasive local soft-tissue remodeling technique with potential application in scar management. Level of Evidence: 5 Lay Summary Electrochemical therapy is a novel treatment that causes spatially selective dermal injury in areas of interest. This study measures the effects of electrochemical therapy when applied to abdominal skin. Electrochemical therapy appears to have beneficial effects by causing a highly localised reduction in collagen content or local softening of tissue, which is consistent with other studies on scar therapies, including chemexfoliation, radiofrequency technologies, and lasers. However, electrochemical therapy can be performed at a fraction of the costs of these aforementioned modalities.

scholarly journals Lead Recovery from Solid Residues of Copper Industry Using Triethylenetetramine Solution

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 546
Author(s):  
Mateusz Ciszewski ◽  
Andrzej Chmielarz ◽  
Zbigniew Szołomicki ◽  
Michał Drzazga ◽  
Katarzyna Leszczyńska-Sejda
Keyword(s):  
Lead Extraction ◽  
Pressure Leaching ◽  
Base Metals ◽  
Lead Carbonate ◽  
Pure Lead ◽  
Industrial Processing ◽  
High Temperature And Pressure ◽  
Lead Recovery ◽  
Temperature And Pressure ◽  
Increasing Temperature

Industrial processing of mineral ores and concentrates generates large amounts of solid residues, which can be landfilled or further processed to recover selected elements depending on its economical profitability. Pressure leaching is a technology enabling high recovery of base metals like copper and zinc, transferring others like lead and iron to the solid residue. High temperature and pressure of such leaching leads to formation of sparingly soluble lead jarosite (plumbojarosite). The load of lead landfilled as solid residues resulting from such operation is so big that its recovery is perspective and crucial for waste-limiting technologies. This paper is devoted to lead extraction from pressure leaching residues using triethylenetetramine solution and then its precipitation as a commercial lead carbonate. The highest obtained recovery of lead was 91.3%. Additionally, presented technology allows to manage and recycle amine solution and reuse solid products. Produced pure lead carbonate can be directly added to smelting, not increasing temperature within the furnace.

Evaluation of interfacial pH change during water splitting at pulsed regime using finite element method

2021 ◽  
Author(s):  
Gabriel Wosiak ◽  
Mariana C. Silva ◽  
Jeyse da Silva ◽  
Evaldo B. Carneiro-Neto ◽  
Mauro C. Lopes ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Water Splitting ◽  
Ph Change ◽  
Pulsed Regime ◽  
Element Method

scholarly journals Syngenetic rapid growth of ellipsoidal silica concretions with bitumen cores

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hidekazu Yoshida ◽  
Ryusei Kuma ◽  
Hitoshi Hasegawa ◽  
Nagayoshi Katsuta ◽  
Sin-iti Sirono ◽  
...  
Keyword(s):  
Organic Matter ◽  
Early Diagenesis ◽  
Ph Change ◽  
Carbon Preference Index ◽  
Diffusion Growth ◽  
Silica Precipitation ◽  
Precipitated Silica ◽  
Preference Index ◽  
Decomposition Of Organic Matter ◽  
Growth Diagram

AbstractIsolated silica concretions in calcareous sediments have unique shapes and distinct sharp boundaries and are considered to form by diagenesis of biogenic siliceous grains. However, the details and rates of syngenetic formation of these spherical concretions are still not fully clear. Here we present a model for concretion growth by diffusion, with chemical buffering involving decomposition of organic matter leading to a pH change in the pore-water and preservation of residual bitumen cores in the concretions. The model is compatible with some pervasive silica precipitation. Based on the observed elemental distributions, C, N, S, bulk carbon isotope and carbon preference index (CPI) measurements of the silica-enriched concretions, bitumen cores and surrounding calcareous rocks, the rate of diffusive concretion growth during early diagenesis is shown using a diffusion-growth diagram. This approach reveals that ellipsoidal SiO2 concretions with a diameter of a few cm formed rapidly and the precipitated silica preserved the bitumen cores. Our work provides a generalized chemical buffering model involving organic matter that can explain the rapid syngenetic growth of other types of silica accumulation in calcareous sediments.

scholarly journals Pyrite (FeS2)-supported ultrafiltration system for removal of mercury (II) from water

2021 ◽  
Author(s):  
Dong Suk Han ◽  
Kawsher M. D. Solayman ◽  
Ho Kyong Shon ◽  
Ahmed Abdel-Wahab
Keyword(s):  
Membrane Filter ◽  
Pyrite Surface ◽  
Ph Change ◽  
Filtration Process ◽  
Sem Images ◽  
Flux Decline ◽  
Cake Layer ◽  
Water Effects ◽  
Almost All ◽  
Over Time

AbstractThis study investigated the Hg(II) removal efficiencies of the reactive adsorbent membrane (RAM) hybrid filtration process, a removal process that produces stable final residuals. The reaction mechanism between Hg(II) and pyrite and the rejection of the solids over time were characterized with respect to flux decline, pH change, and Hg and Fe concentration in permeate water. Effects of the presence of anions (Cl−, SO42−, NO3−) or humic acid (HA) on the rejection of the Hg(II)-contacted pyrite were studied. The presence of both HA and Hg(II) increased the rate of flux decline due to the formation of irreversible gel-like compact cake layers as shown in the experimental data and modeling related to the flux decline and the SEM images. Stability experiments of the final residuals retained on the membrane using a thiosulfate solution (Na2S2O3) show that the Hg(II)-laden solids were very stable due to little or no detection of Hg(II) in the permeate water. Experiment on the possibility of continuously removing Hg(II) by reusing the Hg/pyrite-laden membrane shows that almost all Hg(II) was adsorbed onto the pyrite surface regardless of the presence of salts or HA, and the Hg(II)-contacted pyrite residuals were completely rejected by the DE/UF system. Therefore, a membrane filter containing pyrite-Hg(II) could provide another reactive cake layer capable of further removal of Hg(II) without post-chemical treatment for reuse.

Pulsatile release from pH triggered imidazoline switchable surfactant liposomes

RSC Advances ◽  
2016 ◽  
Vol 6 (62) ◽  
pp. 56859-56866 ◽  
Author(s):  
Dylan Y. Hegh ◽  
Sean M. Mackay ◽  
Eng Wui Tan
Keyword(s):  
Lipid Membrane ◽  
Ph Change ◽  
Pulsatile Release

The incorporation of an imidazoline (IDZ) based switchable surfactant into the lipid membrane of a liposome produces a system that can be triggered to release its solute upon pH change.

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