TY - JOUR
T1 - Tris(2-ethylhexyl)phosphine oxide as an effective solvent mediator for constructing a serotonin-selective membrane electrode
AU - Ueda, Keisuke
AU - Yonemoto, Rei
AU - Komagoe, Keiko
AU - Masuda, Kazufumi
AU - Hanioka, Nobumitsu
AU - Narimatsu, Shizuo
AU - Katsu, Takashi
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Scientific Research (KAKENHI 16590027) from the Japan Society for the Promotion of Science.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006/4/13
Y1 - 2006/4/13
N2 - A series of solvent mediators containing a phosphoryl (P{double bond, long}O) group, such as tris(2-ethylhexyl)phosphate, bis(2-ethylhexyl) 2-ethylhexylphosphonate, 2-ethylhexyl bis(2-ethylhexyl)phosphinate, and tris(2-ethylhexyl)phosphine oxide, were used to construct serotonin-selective membrane electrodes. We found that replacing the alkoxy groups attached to phosphorus atoms in P{double bond, long}O groups with alkyl groups strengthened the response of the electrode to serotonin, suppressing remarkably interference from inorganic cations, such as Na+. Thus, an electrode combining tris(2-ethylhexyl)phosphine oxide with an ion-exchanger, sodium tetrakis[3,5-bis(2-methoxyhexafluoro-2-propyl)phenyl]borate, gave a detection limit of 9 × 10-6 M with a slope of 55.2 mV per concentration decade in physiological saline containing 150 mM NaCl and 10 mM NaH2PO4/Na2HPO4 (pH 7.4). This is the best detection limit of any serotonin-selective electrode developed to date. The selectivity of this electrode for serotonin was over 103 times that for inorganic cations, such as Na+ and K+, and lipophilic quaternary ammonium ions, such as acetylcholine and (C2H5)4N+. Using the electrode, we measured the amount of serotonin released from platelets and found that the results agreed well with those obtained by a conventional fluorimetric assay of serotonin.
AB - A series of solvent mediators containing a phosphoryl (P{double bond, long}O) group, such as tris(2-ethylhexyl)phosphate, bis(2-ethylhexyl) 2-ethylhexylphosphonate, 2-ethylhexyl bis(2-ethylhexyl)phosphinate, and tris(2-ethylhexyl)phosphine oxide, were used to construct serotonin-selective membrane electrodes. We found that replacing the alkoxy groups attached to phosphorus atoms in P{double bond, long}O groups with alkyl groups strengthened the response of the electrode to serotonin, suppressing remarkably interference from inorganic cations, such as Na+. Thus, an electrode combining tris(2-ethylhexyl)phosphine oxide with an ion-exchanger, sodium tetrakis[3,5-bis(2-methoxyhexafluoro-2-propyl)phenyl]borate, gave a detection limit of 9 × 10-6 M with a slope of 55.2 mV per concentration decade in physiological saline containing 150 mM NaCl and 10 mM NaH2PO4/Na2HPO4 (pH 7.4). This is the best detection limit of any serotonin-selective electrode developed to date. The selectivity of this electrode for serotonin was over 103 times that for inorganic cations, such as Na+ and K+, and lipophilic quaternary ammonium ions, such as acetylcholine and (C2H5)4N+. Using the electrode, we measured the amount of serotonin released from platelets and found that the results agreed well with those obtained by a conventional fluorimetric assay of serotonin.
KW - Ion-selective electrode
KW - Platelet
KW - Potentiometry
KW - Serotonin determination
KW - Solvent mediator
KW - Tris(2-ethylhexyl)phosphine oxide
UR - http://www.scopus.com/inward/record.url?scp=33646061944&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33646061944&partnerID=8YFLogxK
U2 - 10.1016/j.aca.2006.02.001
DO - 10.1016/j.aca.2006.02.001
M3 - Article
AN - SCOPUS:33646061944
VL - 565
SP - 36
EP - 41
JO - Analytica Chimica Acta
JF - Analytica Chimica Acta
SN - 0003-2670
IS - 1
ER -