Preparation of a New Copper/Mercury‐Based Amalgam Electrode with Minimal Mercury Content and Its Application for the Determination of Azathioprine in Biological Fluids

Abstract

Herein, a new copper/mercury‐based amalgam electrode with 45 wt % copper was introduced. An amalgam electrode with the lowest mercury content among all amalgam electrodes, reported so far,was introduced. The method of making and activating the electrode was investigated and the working conditions were established. The as‐prepared electrode was employed to determine azathioprine(Aza) using differential pulse adsorptive stripping voltammetry (DPASV) method. The required factors were considered for the electrode voltammetric response to evaluate and optimize Aza level. The proper response of this electrode was obtained in Brinton‐Robinson buffer(BRB) (pH 2) at −0.15 V for 200 seconds. The electrode response to the target compound was linear in the concentration range from 0.04 to 1.0 μM. The detection limit was found to be about 1.6×10−8 M. The relative standard deviation (RSD) for 5 determinations was obtained to be about 3.5 % (the average of RSDs calculated for all concentrations, represented in the calibration curve). The method was successfully applied for Aza determination in plasma and urine samples which led to satisfactory results. It can be concluded that the presence of high levels of potential interfering agents such as ascorbic acid and cysteine did not affect the Aza determination.

Selective Methane Oxidation to Acetic Acid Using Molecular Oxygen over a Mono-Copper Hydroxyl Catalyst

“…No acetic acid was detected in the liquid phase when the methane oxidation was carried out in the absence of MOF catalyst (entry 2, Table S1, SI). The reaction with a drop of mercury did not affect the yield of CH 3 CO 2 H, suggesting that copper nanoparticles or any leached metallic copper particulates were not the active catalysts (Section 3.3, SI) . The production of CH 3 CO 2 H ceased after removing the MOF from the reaction mixture, indicating that the catalytic moiety is located within the solid MOF (Figure S6, SI).…”

“…The reaction with a drop of mercury did not affect the yield of CH 3 CO 2 H, suggesting that copper nanoparticles or any leached metallic copper particulates were not the active catalysts (Section 3.3, SI). 87 The production of CH 3 CO 2 H ceased after removing the MOF from the reaction mixture, indicating that the catalytic moiety is located within the solid MOF (Figure S6, SI). A catalytic reaction with 6 bar O 2 and 30 bar N 2 instead of CH 4 was conducted at 115 °C in water for 40 h. In this reaction, no carbon-containing product was formed, suggesting CH 4 as the sole carbon source for CH 3 CO 2 H formation (entry 3, Table 1).…”