A new electrochemical sensor based on task-specific ionic liquids-modified palm shell activated carbon for the determination of mercury in water samples.

Ahmed Abu Ismaiel,Rozita Yusoff,Mohamed Kheireddine Aroua

doi:10.3390/s140713102

Ahmed Abu Ismaiel, Rozita Yusoff + Show 1 more

Open Access

https://doi.org/10.3390/s140713102

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Journal: Sensors (Basel, Switzerland)	Publication Date: Jul 21, 2014
Citations: 50	License type: CC BY 4.0

Affiliation: University of Malaya

Abstract

In this study, a potentiometric sensor composed of palm shell activated carbon modified with trioctylmethylammonium thiosalicylate (TOMATS) was used for the potentiometric determination of mercury ions in water samples. The proposed potentiometric sensor has good operating characteristics towards Hg (II), including a relatively high selectivity; a Nernstian response to Hg (II) ions in a concentration range of 1.0 × 10−9 to 1.0 × 10−2 M, with a detection limit of 1 × 10−10 M and a slope of 44.08 ± 1.0 mV/decade; and a fast response time (∼5 s). No significant changes in electrode potential were observed when the pH was varied over the range of 3–9. Additionally, the proposed electrode was characterized by good selectivity towards Hg (II) and no significant interferences from other cationic or anionic species.

Highlights

Mercury is a major water pollutant of high concern, producing severe ailments in living beings, including mental retardation
These methods have good sensitivity, and well controlled experimental conditions. They have several disadvantages, such as the use of expensive apparatus, complicated operation, high operation and maintenance costs, and the requirement of well controlled experimental conditions. Because of their advantages in terms of low cost, easy fabrication, simplicity, sensitivity and fast response time, potentiometric sensors based on ion selective electrodes have attracted much attention in electro-analytical chemistry and have been successfully used to determine trace levels of hazardous pollutants such as mercury [12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29]
The slope of the calibration curve (44.08 mV/dec) is close to that predicted theoretically by the Nernst equation (58.16 mV/dec for monovalent cations), which may be attributed to the formation of monovalent mercury complexes on the electrode surface

Summary

Introduction

Mercury is a major water pollutant of high concern, producing severe ailments in living beings, including mental retardation. Several analytical techniques, including, cold vapor atomic absorption spectrometry (CV-AAS) [1,2,3], inductively coupled plasma optical emission spectrometry (ICP-OES) [4,5], X-ray fluorescence spectrometry [6], inductively coupled plasma mass spectrometry (ICP-MS) [7,8] and cold vapour atomic fluorescence spectrometry (CV-AFS) [9,10,11] have been applied for the determination of trace amounts of mercury in analytical samples These methods have good sensitivity, and well controlled experimental conditions. Because of their advantages in terms of low cost, easy fabrication, simplicity, sensitivity and fast response time, potentiometric sensors based on ion selective electrodes have attracted much attention in electro-analytical chemistry and have been successfully used to determine trace levels of hazardous pollutants such as mercury [12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29]

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