Buffer solution

About: Buffer solution is a research topic. Over the lifetime, 6948 publications have been published within this topic receiving 112440 citations. The topic is also known as: pH buffer & buffer.

Simultaneous absorption and oxidation of no and so2 by aqueous solutions of sodium chlorite

Abstract: Complete and simultaneous removal of NO and SO2 is achieved in a laboratory bubble column reactor at about room temperature using aqueous solutions of NaClO2 buffered with Na2HPO4and KH2PO4The influence of reaction medium chemistry (pH and concentrations of buffer and NaOH) on NOx and SO2 removal efficiencies was also evaluated. The buffered NaClO2 solution is determined to be more effective in absorbing NOx and SO2 and in controlling chlorine dioxide (ClO2) leakage. The presence of SO2 greatly reduces the scrubbing solution absorption rate for NO as evidenced by shorter breakthrough times, irrespective of the absorbent solution used. The scrubbing solution pH is determined to be very critical in the simultaneous absorption and oxidation of NO and SO2. NO2 control is enhanced significantly as the buffer concentration increases from 0.1 M to 0.5 M, with no NO2 detected in the effluent gas at buffer concentration levels ≥ 0.5 M. Optimal removal efficiencies were observed at the following conditions...

Electrochemical detection of 4-nitrophenol based on biomass derived activated carbons

Abstract: A novel method for detecting an environmental pollutant, 4-nitrophenol (4-NP), by exploiting biomass-derived activated carbon (AC) is reported. The electrochemical performances of the 4-NP sensor were assessed by cyclic and linear sweep voltammetries. The presence of oxygen surface functional groups and heteroatoms (72.6% C, 6.1% H, 6.5% N, and 7.5% S) in the biomass-derived AC with high surface area (1555 m2 g−1) are found to be responsible for the excellent catalytic activities and reversible redox behaviors observed during the detection of 4-NP. The effects of pH of the electrolyte buffer solution, accumulated potential and duration as well as the analyte concentration on the electrocatalytic performance of the sensor were investigated. Consequently, a linear correlation between the cathodic reduction peak current with 4-NP concentration up to 500 μM with a detection limit and sensitivity of 0.16 μM and 5.810 μA μM−1 cm−2, respectively, were observed over the AC-modified GCE in 0.05 M acetate buffer solution (pH 5.0), surpassing the existing modified electrodes in the literature. The facile 4-NP sensor thus implemented is also advantageous for its simplicity, stability, reliability, durability, and low cost, rendering practical applications for real sample systems.

Degradation of nonalternating poly(ester amides)

Abstract: Two types of poly(ester-amide)s were prepared by convenient methods for degradation studies. Both were found to be degradable under attack of Fusarium monoliforme. These copolymers are also degradable by hydrolysis in pH 7.4 buffer solution, however, at much slower rates

NIR-emitting colloidal quantum dots having 26% luminescence quantum yield in buffer solution.

Abstract: We report PbS quantum dot lumophores emitting in the near-infrared. The lumophores are stable for at least 5 days stored in physiologically relevant pH 6−8 buffer, have sub-10 nm hydrodynamic diame...

Simultaneous determination of 2-nitrophenol and 4-nitrophenol based on the multi-wall carbon nanotubes Nafion-modified electrode.

Abstract: In this work, multi-wall carbon nanotubes (MWNT) were conveniently dispersed into Nafion–ethanol solution, and the MWNT–Nafion-modified glassy carbon electrode (GCE) was described for the simultaneous determination of 2-nitrophenol and 4-nitrophenol. At pH 4.0 phosphate buffer, the reduction peak currents of 2-nitrophenol (at –0.8 V) and 4-nitrophenol (at −1.0 V) increase significantly at the MWNT–Nafion-modified GCE, in comparison with that at the Nafion-modified GCE and the bare GCE. The experimental parameters, such as solution pH of phosphate buffer, accumulation potential and time, and the amounts of MWNT–Nafion onto the GCE surface, were optimized. The reduction peak currents are linear with the concentration of 2-nitrophenol from 5×10−8 to 1×10−5 mol L−1 and with that of 4-nitrophenol from 1×10−7 to 1×10−5 mol L−1. The detection limits after 3-min accumulation are 1×10−8 mol L−1 for 2-nitrophenol and for 4×10−8 mol L−1 for 4-nitrophenol. This modified electrode was applied to direct determination of 2-nitrophenol and 4-nitrophenol in lake water samples.