A novel Ho(III) sensor based on N,N'-bis(2- pyridinecarboxamide)-1,2-benzene as a neutral ion carrier

Abstract

N,N'-bis(2-piridinacarboxamida)-1,2-benzeno (H 2 BPB) apresentou um comportamento seletivo e sensível, frente ao íon Ho(III), em comparação a um grande número de íons de metais de transição interna, representativos e de lantanídeos, tendo sido portanto, aplicado como um ionóforo neutro para preparação de uma membrana sensora Ho(III), com alta seletividade e sensitividade. As membranas também contêm tetraquis(p-clorofenil) borato de potássio (KTpClPB) como um aditivo aniônico, e foram testadas pelo uso de diferentes solventes mediadores plastificantes, tais como benzil acetato (BA), nitrobenzeno (NB), e éter o-nitrofeniloctil (NPOE). A composição ótima encontrada foi H 2 BPB-PVC-KTpClPB-BA, com razão de 6,0: 30,0: 4,0: 60,0, respectivamente. Com uma resposta Nernstiniana de 19,6 ± 0,2 mV per década de atividade de Ho(III), o intervalo linear encontrado para o sensor foi relativamente grande (de 1,0×10-5 a 1,0 ×10-2 mol L-1), podendo trabalhar bem no intervalo de pH de 3,0 a 11,5. O limite de detecção mais baixo (LDL) calculado para o sensor foi de 8,0 ×10-6 mol L-1. A excelente seletividade do sensor proposto para Ho(III), considerando os íons metálicos mais comuns e, especialmente todos os íons lantanídeos, é uma outra vantagem deste sensor. O sensor foi usado com sucesso como eletrodo indicador na titulação de 25 mL de solução de íons Ho(III) a 1,0 × 10-4 mol L-1 , com EDTA a 1,0 × 10-2 mol L-1 , e vice-versa. Este é o primeiro sensor seletivo para Ho(III). N,N'-bis(2-pyridinecarboxamide)-1,2-benzene (H 2 BPB) was found to have a selective and sensitive behavior towards Ho(III) ion, in comparison to a large number of lanthanide, inner transition and representative metal ions and was hence applied as a neutral ionophore, for preparing an Ho(III) membrane sensor, with high selectivity and sensitivity. The membranes, also contain potassium tetrakis(p-chlorophenyl) borate as an anionic additives, and were tested by using different plasticizing solvent mediators such as benzyl acetate (BA), nitrobenzene (NB), and o-nitrophenyloctyl ether (NPOE). The optimum composition was found to be H 2 BPB-PVC-KTpClPB-BA with the ratios of 6.0: 30.0: 4.0: 60.0, respectively. Having a Nernstian response of 19.6 ± 0.2 mV per decade of Ho(III) activity, the linear range of the sensor was found to be relatively wide (from 1.0×10-5 to 1.0 ×10-2 mol L-1). It can work well in the pH range of 3.0-11.5. The lower detection limit (LDL) of the sensor was calculated to be 8.0 ×10-6 mol L-1. The excellent Ho(III)-selectivity of the proposed sensor with regard to most common metal ions, and especially, all lanthanide ions, is another advantage that can be mentioned about this sensor. The sensor was successfully used as an indicator electrode for titration of 25 mL of a 1.0 × 10-4 mol L-1 Ho(III) ions with a 1.0 × 10-2 mol L-1 EDTA, and vise versa. To the best of our knowledge this is the first Ho(III)-selective sensor.

A Ho(III) potentiometric polymeric membrane sensor based on a new four dentate neutral ion carrier

“…The obtained selectivity coefficients revealed that these cations cannot disturb the function of the proposed Ho 3+ membrane sensor. Table 3 compared the detection limit, concentration range, response time, and selectivity coefficients for previously reported and proposed sensor [12][13][14][15][16][17]. As seen, the proposed membrane sensor based on H 2 Me 2 bpb shows superior selectivity to the previous reported ones.…”

“…Ionophores in references [13] and [14] cannot form a wrapped around complex. The ionophore used in references [15][16][17], are form a family. They are derivatives of symmetric picolinamide.…”

“…Although there are a few reports on holmium potentiometric sensors [12][13][14][15][16][17], there is a need to find more selective ionophores which can form a selective complex with one of the lanthanides more than others. In this work, N-(4,5-dimethyl-2-(picolinamido)phenyl)picolinamide (H 2 Me 2 bpb) ( Fig.…”

One decade of research on ion-selective electrodes in Iran (1996–2006)

“…Other sensors include Eu 3+ [171,172], Gd 3+ [173][174][175][176], Tb 3+ [177,178], Dy 3+ [179,180], Ho 3+ [181,182], Er 3+ [183], Tm 3+ [184,185], Yb 3+ [186][187][188] PMEs, in addition to one Lu 3+ PME [189] and two uranyl PMEs and GCE [190,191]. The minimum detection limit among all of these sensors is reported to be 7.0 × 10 -8 for uranyl ion [191], which is a 2,2'- …”

Comparative Study of Holmium (III) Selective Sensors Based on Thiacalixarene and Calixarene Derivatives as an Ionophore

“…The potentiometric sensors based on ion-selective electrode are the best analytical method for such determination because they offer advantages such as selectivity, sensitivity, low detection limit, simplicity and low cost. [12][13][14][15][16][17][18][19][20][21][22][23][24] A literature survey reveled that few sensors [24][25][26][27][28][29][30][31] have been reported to determine Ho 3+ concentration, but they have low detection limit, narrow concentration range and interference from other ions. Thus, a quick, convenient, fast method is required to determine Ho 3+ in large number of environmental samples.…”