Transmembrane Ion Fluxes for Lowering Detection Limit of Ion-Selective Electrodes

Solid-contact ion-selective electrodes with carbazole-derived ionophores were prepared. They were characterized as acetate sensors, but can be used to determine a number of carboxylates. The potentiometric response characteristics (slope, detection limit, selectivity, and pH sensitivity) of sensors prepared with different membrane compositions (ionophore, ionophore concentration, anion exchanger concentration, and plasticizer) were evaluated. The results show that for the macrocyclic ionophores, a larger cavity provided better selectivity. The sensors exhibited modest selectivity for acetate but good selectivity for benzoate. The carbazole-derived ionophores effectively decreased the interference from lipophilic anions, such as bromide, nitrate, iodide, and thiocyanate. The selectivity, detection limit, and linear range were improved by choosing a suitable plasticizer and by reducing the ionophore and anion exchanger concentrations. The influence of the electrode body’s material upon the composition of the plasticized poly(vinyl chloride) membrane, and thus also upon the sensor characteristics, was also studied. The choice of materials for the electrode body significantly affected the characteristics of the sensors.

Download Full-text

Validation of a Novel Potentiometric Method Based on a Polymeric PVC Membrane Sensor Integrated with Tailored Receptors for the Antileukemia Drug Cytarabine

Polymers ◽

10.3390/polym12061343 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1343 ◽

Cited By ~ 2

Author(s):

Ayman H. Kamel ◽

Abd El-Galil E. Amr ◽

Nashwa H. Ashmawy ◽

Hoda R. Galal ◽

Abdulrahman A. Almehizia ◽

...

Keyword(s):

Detection Limit ◽

Biological Fluid ◽

Pharmaceutical Formulations ◽

Assay Method ◽

Pvc Membrane ◽

Therapeutic Drug ◽

Ion Selective Electrodes ◽

Easy Method ◽

Potentiometric Response ◽

Sensory Element

A simple, rapid and easy method is proposed for the detection of a cytostatic therapeutic drug, cytarabine, in real samples. The method is based on potentiometric transduction using prepared and characterized new ion-selective electrodes for cytarabine. The electrodes were integrated with novel man-tailored imprinted polymers and used as a sensory element for recognition. The electrodes revealed a remarkable potentiometric response for cytarabine over the linearity range 1.0 × 10−6–1.0 × 10−3 M at pH 2.8–4 with a detection limit of 5.5 × 10−7 M. The potentiometric response was near-Nernstian, with average slopes of 52.3 ± 1.2 mV/decade. The effect of lipophilic salts and plasticizer types on the potentiometric response was also examined. The electrodes exhibited an enhanced selectivity towards cytarabine over various foreign common ions. Validation and verification of the presented assay method are demonstrated by evaluating the method ruggedness and calculating the detection limit, range of linearity, accuracy (trueness), precision, repeatability (within-day) and reproducibility (between-days). The proposed ion-selective electrodes revealed good performance characteristics and possible application of these electrodes for cytarabine monitoring in different matrices. The electrodes are successfully applied to cytarabine determination in spiked biological fluid samples and in pharmaceutical formulations.

Download Full-text

Steady-State Model Calculations Predicting the Influence of Key Parameters on the Lower Detection Limit and Ruggedness of Solvent Polymeric Membrane Ion-Selective Electrodes

Electroanalysis ◽

10.1002/(sici)1521-4109(199907)11:10/11<673::aid-elan673>3.0.co;2-w ◽

1999 ◽

Vol 11 (10-11) ◽

pp. 673-680 ◽

Cited By ~ 38

Author(s):

Titus Zwickl ◽

Thomasz Sokalski ◽

Ernö Pretsch

Keyword(s):

Steady State ◽

Detection Limit ◽

State Model ◽

Polymeric Membrane ◽

Ion Selective Electrodes ◽

Model Calculations ◽

Lower Detection Limit ◽

Steady State Model ◽

Lower Detection

Download Full-text

Potential Drifts of Solid-Contacted Ion-Selective Electrodes Due to Zero-Current Ion Fluxes Through the Sensor Membrane

Electroanalysis ◽

10.1002/1521-4109(200011)12:16<1286::aid-elan1286>3.0.co;2-q ◽

2000 ◽

Vol 12 (16) ◽

pp. 1286-1292 ◽

Cited By ~ 213

Author(s):

Monia Fibbioli ◽

Werner E. Morf ◽

Martin Badertscher ◽

Nicolaas F. de Rooij ◽

Ernö Pretsch

Keyword(s):

Ion Fluxes ◽

Ion Selective Electrodes ◽

Sensor Membrane ◽

Zero Current

Download Full-text

Time-Dependent Phenomena in the Potential Response of Ion-Selective Electrodes Treated by the Nernst−Planck−Poisson Model. Part 2: Transmembrane Processes and Detection Limit

Analytical Chemistry ◽

10.1021/ac900490c ◽

2009 ◽

Vol 81 (12) ◽

pp. 5016-5022 ◽

Cited By ~ 31

Author(s):

Tomasz Sokalski ◽

Witold Kucza ◽

Marek Danielewski ◽

Andrzej Lewenstam

Keyword(s):

Detection Limit ◽

Poisson Model ◽

Time Dependent ◽

Ion Selective Electrodes ◽

Potential Response

Download Full-text

All-plastic, disposable, low detection limit ion-selective electrodes

Analytica Chimica Acta ◽

10.1016/j.aca.2004.07.020 ◽

2004 ◽

Vol 523 (1) ◽

pp. 97-105 ◽

Cited By ~ 67

Author(s):

Agata Michalska ◽

Krzysztof Maksymiuk

Keyword(s):

Detection Limit ◽

Ion Selective Electrodes ◽

Low Detection Limit

Download Full-text

EFFECT OF NATURE OF PLASTICIZER ON CHARACTERISTICS OF ION-SELECTIVE ELECTRODES REVERSIBLE TO DOUBLY CHARGED INORGANIC ANIONS

IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA ◽

10.6060/ivkkt.20206301.6019 ◽

2019 ◽

Vol 63 (1) ◽

pp. 18-22

Author(s):

Yulya V. Matveichuk

Keyword(s):

Detection Limit ◽

Dibutyl Phthalate ◽

Ammonium Salts ◽

Ion Selective Electrodes ◽

Hydrogen Phosphate ◽

Selective Electrode ◽

Lower Detection Limit ◽

Large Dielectric Constant ◽

Lower Detection ◽

Doubly Charged

A study of the effect of the nature of the plasticizer on the characteristics (lower detection limit and selectivity) of electrodes that are reversible to carbonate, hydrogen phosphate, sulfate, selenate, selenite, sulfite, molybdate, tungstate, and thiosulfate ions was carried out. It was found that the membranes of carbonate and hydrophosphate selective electrodes based on quaternary ammonium salts are preferable to plasticize with o-nitrophenyl decyl ether, membranes of sulfate, selenate, selenite-selective electrodes - 1-bromonaphthalene, sulfite, molybdate, tungstate, and thiosulfate selective electrodes - dibutyl phthalate. For sulfate, selenate, and selenite-selective electrodes, there is an improvement in selectivity and a decrease in the detection limit in the series: o-nitrophenyldecyl ether – dibutylphthalate ≈ didecylphthalate ≈ bis (ethylhexyl) sebacinate -1-bromonaphthalene. The replacement of o-nitrophenyldecyl ether with 1-bromonaphthalene leads to a decrease in logKPot for these electrodes by 0.2–1.0 orders of magnitude depending on the interfering ion. The detection limit for sulfate, selenate, and selenite-selective electrodes is reduced by 0.2–0.65 orders of magnitude. For carbonate and hydrogen phosphate selective electrodes from o-nitrophenyldecyl ether to 1-bromonaphthalene, the detection limit decreases, for example, for a carbonate selective electrode by 0.6 orders of magnitude, for a hydrogen phosphate selective electrode by 1 order; the values of logKPot (CO32–, j) decrease by 0.1–0.9 orders of magnitude, and the values of logKPot (HPO42–, j) decrease by 0.6–1.25 orders of magnitude depending on the interfering ion. The results are explained in terms of the theories of Aigen-Denison-Ramzi-Fuoss and Born. The plasticizer that is optimal for carbonate and hydrophosphate selective electrodes has a large dielectric constant ε = 24; for all other electrodes, the optimal plasticizers have lower ε values (ε = 5–6). The use of dibutyl phthalate and 1-bromonaphthalene membranes as plasticizers is consistent with the Aigen-Denison-Ramzi-Fuoss theory, and the use of o-nitrophenyldecyl ether with the Born theory.

Download Full-text