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Rotating electrode potentiometry: lowering the detection limits of nonequilibrium polyion-sensitive membrane electrodes.
Anal Chem 2001; 73(2):332-6AC

Abstract

A rotating electrode configuration is evaluated as a means to lower the detection limits of newly devised polyion-sensitive membrane electrodes (PSEs). Planar potentiometric polycation and polyanion PSEs are prepared by incorporating tridodecylmethylammonium chloride and calcium dinonylnaphthalenesulfonate, respectively, into plasticized PVC or polyurethane membranes and mounting disks of such films on an electrode body housed in a conventional rotating disk electrode apparatus. Rotation of the PSEs at 5000 rpm results in an enhancement in the detection limits toward heparin (polyanion) and protamine (polycation) of at least 1 order of magnitude (to 0.01 unit/mL for heparin; 0.02 microg/mL for protamine) over that observed when the EMF responses of the same electrodes are assessed using a stir-bar to achieve convective mass transport. A linear relationship between omega(-1/2), where omega is the rotating angular frequency, and C1/2, the polyion concentration corresponding to half the total maximum deltaEMF response toward the polyion species, is observed. It is further shown that the rotating polycation sensor can be used as an end-point detector to greatly enhance (relative to nonrotated indicator electrode) the analytical resolution and precision for measurement of low concentrations of heparin when such samples are titrated with protamine. The theoretical basis for lowering the detection limits by rotating PSEs is discussed based on the unique nonequilibrium response mechanism of such sensors.

Authors+Show Affiliations

Department of Chemistry, The University of Michigan, Ann Arbor 48109-1055, USA.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

11199986

Citation

Ye, Q, and M E. Meyerhoff. "Rotating Electrode Potentiometry: Lowering the Detection Limits of Nonequilibrium Polyion-sensitive Membrane Electrodes." Analytical Chemistry, vol. 73, no. 2, 2001, pp. 332-6.
Ye Q, Meyerhoff ME. Rotating electrode potentiometry: lowering the detection limits of nonequilibrium polyion-sensitive membrane electrodes. Anal Chem. 2001;73(2):332-6.
Ye, Q., & Meyerhoff, M. E. (2001). Rotating electrode potentiometry: lowering the detection limits of nonequilibrium polyion-sensitive membrane electrodes. Analytical Chemistry, 73(2), pp. 332-6.
Ye Q, Meyerhoff ME. Rotating Electrode Potentiometry: Lowering the Detection Limits of Nonequilibrium Polyion-sensitive Membrane Electrodes. Anal Chem. 2001 Jan 15;73(2):332-6. PubMed PMID: 11199986.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Rotating electrode potentiometry: lowering the detection limits of nonequilibrium polyion-sensitive membrane electrodes. AU - Ye,Q, AU - Meyerhoff,M E, PY - 2001/2/24/pubmed PY - 2001/3/3/medline PY - 2001/2/24/entrez SP - 332 EP - 6 JF - Analytical chemistry JO - Anal. Chem. VL - 73 IS - 2 N2 - A rotating electrode configuration is evaluated as a means to lower the detection limits of newly devised polyion-sensitive membrane electrodes (PSEs). Planar potentiometric polycation and polyanion PSEs are prepared by incorporating tridodecylmethylammonium chloride and calcium dinonylnaphthalenesulfonate, respectively, into plasticized PVC or polyurethane membranes and mounting disks of such films on an electrode body housed in a conventional rotating disk electrode apparatus. Rotation of the PSEs at 5000 rpm results in an enhancement in the detection limits toward heparin (polyanion) and protamine (polycation) of at least 1 order of magnitude (to 0.01 unit/mL for heparin; 0.02 microg/mL for protamine) over that observed when the EMF responses of the same electrodes are assessed using a stir-bar to achieve convective mass transport. A linear relationship between omega(-1/2), where omega is the rotating angular frequency, and C1/2, the polyion concentration corresponding to half the total maximum deltaEMF response toward the polyion species, is observed. It is further shown that the rotating polycation sensor can be used as an end-point detector to greatly enhance (relative to nonrotated indicator electrode) the analytical resolution and precision for measurement of low concentrations of heparin when such samples are titrated with protamine. The theoretical basis for lowering the detection limits by rotating PSEs is discussed based on the unique nonequilibrium response mechanism of such sensors. SN - 0003-2700 UR - https://www.unboundmedicine.com/medline/citation/11199986/Rotating_electrode_potentiometry:_lowering_the_detection_limits_of_nonequilibrium_polyion_sensitive_membrane_electrodes_ L2 - https://dx.doi.org/10.1021/ac000756g DB - PRIME DP - Unbound Medicine ER -