Reduction of the Anion Interference in Neutral Carrier Liquid-Membrane Electrodes Responsive to Cations

Potentiometric Membrane Electrode for Salicylate Based on an Organotin Complex with a Salicylal Schiff Base of Amino Acid

“…[24][25][26] Since the widely used uncharged carriers are neutral when uncomplexed and the complexes have the same charge as the analyte ion, the respective membranes require the additional incorporation of lipophilic ions of opposite charge to obtain a Nernstian response, 27-29 a decrease in the membrane resistance, 30 a reduction in the coion interferences, 31 and an improvement in the detection limit and optimization of the selectivity. [32][33][34] In practice, alkali salts of tetraphenylborate derivatives are used for cationic-selective membranes and tetraalkylammonium salts for anion-selective membranes.…”

A New Lead(II)-Selective PVC-Coated Graphite Rod Electrode Based on a Schiff Base Complex

“…Moreover, the membrane can be easily regenerated daily by dipping the graphite rod in the stock solution of membrane coating mixture. The higher value of the slope (30.0 ± 0.2 mV per decade) has also indicated the absence of any anion effect, 34 such as is commonly observed in lead electrodes based on PVC.…”

Additive-Salt Effect on Low Detection Limit and Slope Sensitivity in Response of Potassium- and Sodium-Selective Neutral Carrier Based Electrodes and Their Liquid-Membrane Based Ion-Sensitive Field-Effect Transistor

“…They found that the low detection limits and the slope sensitivities of the Vitamin B 1 ISEs improve in the order of TPB<Cesibor<TCPB=TFPB and the order is the same as the increase in the lipophilicity of the ion-exchanger. The fact that the low detection limits and the slope sensitivities of the Vitamin B 1 ISEs improve in the order of TPB< Cesibor<TCPB=TFPB, may be the result of a decrease in the solubility of the TPB derivatives anions from the solvent polymeric sensing-membrane into the sample solution. In analogy with the Vitamin B 1 ISE, the fact that the low detection limit and the slope sensitivity of the K + -ISE based on valinomycin are improved appar- ently in the order of TPB<Cesibor<TCPB<TFPB may be the effect of decreases in the solubility of the sensing-materials composed of complex salt between potassium cation and the neutral carrier and a counter anion, one of the TPB derivatives.…”

“…Sodium tetraphenylborate (NaTPB) and its more lipophilic derivative, tetrakis(pchlorophenyl) borate (K-TCPB), are usually used as the additive salt. These additive salts have been reported to improve electrochemical characteristics of the neutralcarrier based ISEs taking account of the following advantages: reduction or elimination of interference by lipophilic anions 1,2 , reduction of electrical resistance of the sensing membrane 3 , reduction of the electrode response time 4 and enhancement of selectivity. 5,6 Recently, Bakker et al 5,6 have investigated the effect of additive salts on selectivity of the neutral-carrier based ISEs using an electrochemical method.…”