Determination of total mercury in seafood by ion-selective electrodes based on a thiol functionalized ionic liquid

Abstract

A mercury(II) ion-selective electrode with an ionic liquid (IL), 1-methyl-2-butylthioimidazolium bis(trifluoromethanesulphonyl)imide ([CCSim]NTf) as active material was constructed. Parameters affecting the performance of the electrodes such as the dosages of the IL and carbon nanotubes and the aqueous pH values were investigated. Experimental results indicated that the optimal composition of the electrode filling material was 47.6% [CCSim]NTf, 47.6% tetrabutylphosphonium bis(trifluoromethanesulphonyl)imide (TBPNTf) and 4.8% carboxylic multi-walled carbon nanotubes (MWCNTs-COOH). Under the selected conditions, the proposed electrodes showed a good linear response in the concentration range of 10-10 mol L and had a detection limit of 4.1 × 10 mol L. No great interference from common metal ions was found. The proposed electrodes were applied to determine Hg in seafood samples; the results were comparable to those of the direct mercury analyzer.

Application of ionic liquids in ion‐selective electrodes and reference electrodes: A review

“…In both papers [94] and [95] ionic liquids were used in the role of the ionophore, in sensors used to determine mercury(II) and copper(II) ions in food, respectively. ILs in both cases were components of the electrode filling material.…”

Ion-Selective Electrodes in the Food Industry: Development Trends in the Potentiometric Determination of Ionic Pollutants

“…Similar imidazole-based ionophores have been employed in the detection of mercury in food combined with carbon nanomaterials. Miao et al [102] employed an ionic liquid-based matrix for the characterisation of seafood. This device combined an ultra-low detection limit, below the nanomolar level (41 pM), and good selectivity when compared to other common electrolytes, including Na + , Ca 2+ , and K + .…”

Design and Characterization of Electrochemical Sensor for the Determination of Mercury(II) Ion in Real Samples Based upon a New Schiff Base Derivative as an Ionophore

“…Many organic and inorganic compounds have been documented in the literature as ionophores for the synthesis of ion selective electrodes for the determination of Hg 2+ ion in various samples over the last three decades. Crown ether derivatives [19,20], polyvinyl pyridine [21], calix [4]pyrrole amide derivative [22], calixarene derivatives [23][24][25][26][27][28], thiol functionalized ionic liquid [29], amines [30,31], thioureas [25,32], and dithio derivatives [33,34] have all been used as ionophores for designing ISEs of Hg 2+ ions. It's worth mentioning that, some ionic liquids, e.g., 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF 4 ) [35], polypyrrole (PPy) [36], O,O -(2,2 -biphenylene)dithiophosphatepentyl (PenDTF) [37], 1methyl-2-butylthioimidazolium combined with bis(trifluoromethanesulphonyl) imide [29], dimethylglyoxime [38], and 2-mercaptobenzimidazol (2MBI) [39] are widely employed as ionophores in ISEs of Hg(II) ions.…”