scholarly journals A Reversible Spectrophotometric Method Based on a Coupled Microfluidic Chip for Highly Selective Ammonium Detection

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Hao Zhou ◽  
Yilin Song ◽  
Zheng Yang
Keyword(s):  
High Selectivity ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Gas Diffusion ◽  
Real Samples ◽  
Spectrum Change ◽  
The Stability ◽  
Detection Effect ◽  
Spectrum Data ◽  
Diffusion Membrane

A coupled chip aiming at economical and highly selective ammonium detection was fabricated. It consisted of a reaction chip, a gas-diffusion chip, and a detection chip. Zinc tetraphenylporphyrin dyed on the cation-exchange resin microbeads was used as the indicating material to avoid excess consumption for its reversibility. PDMS was selected as the material of the gas-diffusion membrane. A portable spectrometer was applied for spectrum analysis. By analysis of spectrum change, the high selectivity was confirmed because no component had interference on detection effect. Good performance was shown for all the tested concentrations (0.2–50 mg·L−1). The stability and reversibility were also judged by the spectrum data obtained from the indicating process and the recovering process. Finally, real samples containing ammonium were tested and the results were compared to those came from a standard method to confirm the accuracy of our method.

Measurement of free-circulating cis-dichlorodiammineplatinum(II) in plasma.

1977 ◽  
Vol 23 (12) ◽  
pp. 2258-2262 ◽  
Author(s):  
S J Bannister ◽  
L A Sternson ◽  
A J Repta ◽  
G W James
Keyword(s):  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Free Drug ◽  
Platinum Compounds ◽  
Minimum Thickness ◽  
X Ray ◽  
Drug Plasma ◽  
Detection Capabilities ◽  
The Stability ◽  
Bound Drug

Abstract Dichlorodiammineplatinum(II) is an anti-neoplastic agent that is currently undergoing clinical evaluation. We describe an analytical method for monitoring the free drug (or its breakdown products) in plasma. The method is able to distinguish between free and protein-bound drug. Plasma samples are deproteinized by centrifugal ultrafiltration. The platinum in the ultrafiltrate is converted to a cationic species by reaction with ethylenediamine and then collected on paper impregnated with cation-exchange resin. This process concentrates the samples, increases the stability of the platinum compounds (by removing the compound from solution), and places the sample in a uniform matrix of minimum thickness, which maximizes detection capabilities. Platinum was measured directly on the ion-exchange disks by X-ray fluorescence. The detection limit for free drug is 240 microgram/liter of plasma at the 3s level and fluorescence intensity is linearly related to drug concentration in the range from 570 to 5700 microgram/liter.

Bloat investigations

1955 ◽  
Vol 46 (2) ◽  
pp. 257-266 ◽  
Author(s):  
W. S. Ferguson ◽  
R. A. Terry
Keyword(s):  
Dairy Cows ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Single Test ◽  
Stable Foam ◽  
Egg Albumin ◽  
Surface Active Agents ◽  
Surface Active ◽  
Household Detergents ◽  
The Stability

An account is given of experimental work carried out at Jealott's Hill on bloat.Bloat was produced in dairy cows and sheep by dosing with lucerne juice. Sheep proved convenient test animals and were used in most of the tests described.Parenteral and intravenous administration of the flavone quercetin, which inhibits the activity of smooth muscle, did not cause bloat even in the presence of cyanide. It is unlikely that flavones are concerned in bloat.Fractionation of bloat-provoking lucerne juice showed that activity was retained after (a) precipitation of chloroplastic material, and (b) passage of clear juice through an anion or cation exchange resin. This suggests that the bloat-provoking factor is non-ionic and not adsorbed on resins—properties shown by saponinis.Dosing sheep with lucerne saponins, four other saponins, egg albumin and a synthetic foaming compound failed to produce bloat.Two household detergents and a number of surface-active agents did not relieve bloat, but foam-breaking compounds were very effective.A synthetic inorganic saliva and cow's saliva did not prevent bloat in sheep and from the single test made with cow's saliva it is not possible to say if it increased the severity of bloat.It is concluded that the formation of a stable foam is a major factor in lucerne bloat and that food constituents, other than saponins, and the physical condition of the rumen ingesta probably influence the stability of the foam.

Stabilization of pH in Solid-matrix Hydroponic Systems

HortScience ◽  
1993 ◽  
Vol 28 (10) ◽  
pp. 981-984 ◽  
Author(s):  
Jay Frick ◽  
Cary A. Mitchell
Keyword(s):  
Seed Yield ◽  
Seed Oil ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Solid Matrix ◽  
Resin Bead ◽  
Resin Beads ◽  
Hydroponic Systems ◽  
Ethanesulfonic Acid ◽  
Substrate Ph

2-[N-morpholino] ethanesulfonic acid (MES) buffer or Amberlite DP-1 (cation-exchange resin beads) were used to stabilize substrate pH of passive-wicking, solid-matrix hydroponic systems in which small canopies of Brassica napus L. (CrGC 5-2, genome: ACaacc) were grown to maturity. Two concentrations of MES (5 or 10 m m) were included in Hoagland 1 nutrient solution. Alternatively, resin beads were incorporated into the 2 vermiculite: 1 perlite (v/v) growth medium at 6% or 12% of total substrate volume. Both strategies stabilized pH without toxic side effects on plants. Average seed yield rates for all four pH stabilization treatments (13.3 to 16.9 g·m-2·day-1) were about double that of the control (8.2 g·m-2·day-1), for which there was no attempt to buffer substrate pH. Both the highest canopy seed yield rate (16.9 g·m-2·day-1) and the highest shoot harvest index (19.5%) occurred with the 6% resin bead treatment, even though the 10 mm MES and 12% bead treatments maintained pH within the narrowest limits. The pH stabilization methods tested did not significantly affect seed oil and protein contents.

Synthesis of 3,4-Dihydropyrano[c]chromenes Using Carbon Microsphere Supported Copper Nanoparticles (Cu-NP/C) Prepared from Loaded Cation Exchange Resin as a Catalyst

2019 ◽  
Vol 16 (2) ◽  
pp. 288-293
Author(s):  
Yogesh W. More ◽  
Sunil U. Tekale ◽  
Nitishkumar S. Kaminwar ◽  
László Kótai ◽  
Tibor Pasinszki ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Cation Exchange ◽  
Copper Nanoparticles ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Environmentally Benign ◽  
High Yield ◽  
Carbon Microsphere ◽  
Catalytic Material ◽  
Operational Simplicity

Aim and Objective: The present study was performed with the aim to develop an efficient and environmentally benign protocol for the synthesis of biologically siginifcant 3, 4-dihydropyrano[c]chromenes using a new catalytic material. The protocol involves the use of a reusable, environment friendly materials and solvents with operational simplicity. Materials and Methods: Carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin were synthesized, characterized with well versed analytical techniques such as XRD, SEM and Raman spectroscopy and the synthesized material was used as a catalyst for the environmentally benign synthesis of 3,4-dihydropyrano[c]chromenes. Results: The formation of carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin was confirmed by XRD, SEM and Raman spectroscopy which was employed as a heterogeneous material for the synthesis of 3,4-dihydropyrano[c]chromenes. The products formed were characterized by the analysis of spectroscopic data - NMR, IR and mass. The safe catalytic system offers several advantages including operational simplicity, environmental friendliness, high yield, and reusability of catalyst and green chemical transformation. Conclusion: Herein we report an easy and efficient protocol for the one-pot synthesis of dihydropyrano[ c]chromenes using environmentally benign MCR approach in ethanol as the green solvent. The method developed herein constitutes a valuable addition to the existing methods for the synthesis of titled compounds.

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