Electroanalytical Determination of Morpholine as a Corrosion Inhibitor at a Cathodically Pretreated Boron-Doped Diamond Electrode
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2018-11-20 |
| Journal | Analytical Letters |
| Authors | Luana Rianne Rocha, Eliane DāElia, Roberta Antigo Medeiros, CĆ©sar Ricardo Teixeira Tarley |
| Institutions | Universidade Estadual de Londrina, Universidade Federal do Rio de Janeiro |
| Citations | 13 |
Abstract
Section titled āAbstractāAn electroanalytical method for the determination of morpholine, a corrosion inhibitor, was developed at a cathodically pretreated boron-doped diamond electrode (BDDE). The voltammetric response of morpholine at the BDDE in 0.1 mol Lā1 KCl (pH 10) shows an irreversible oxidation process at approximately 1.3 V vs. Ag/AgCl in 3.0 mol Lā1 KCl. Using cyclic voltammetry, the number of electrons involved in the morpholine electroxidation mechanism was found to be 1. The application of chronoamperometry showed that the apparent diffusion coefficient (D0) was 2.99 Ć 10ā6 cm2 sā1. Using square wave voltammetry under the optimized conditions (frequency of 30.0 Hz, pulse amplitude of 100 mV and step potential of 20 mV at pH 10.0), the developed method provided limits of detection and quantification of 2.1 and 6.9 mg Lā1, respectively, with a linear range from 5.0 to 100.0 mg Lā1 (r = 0.991). Intraday (n = 10) and interday (two consecutive day) precision values assessed as the relative standard deviation for solutions containing 30.0, 60.0, and 90.0 mg Lā1 of morpholine were from 0.41 to 5.86% and 0.92 to 3.19%, respectively. The feasibility of the method for the interference-free determination of morpholine was verified by the analysis of synthetic boiler water samples containing CaCO3, Na2SO3, Na3PO4, FeCl3, and humic acid as organic matter. In addition, hydrazine was added as a possible interfering compound because of its widespread use in corrosion inhibition. Recovery values from 90.9 to 109.4% were obtained in the synthetic boiler water, thereby attesting to the accuracy of the method.
Tech Support
Section titled āTech SupportāOriginal Source
Section titled āOriginal SourceāReferences
Section titled āReferencesā- 1978 - NR-13 Caldeiras, Vasos de PressĆ£o e Tubulação
- 1997 - Recommendations for treatment of water for steam boilers and water heaters: BS 2486:1997