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Flow injection potentiometry by poly(vinyl chloride)-membrane electrodes with substituted azacrown ionophores for the determination of lead(II) and mercury(II) ions

Citation

Yang, XH and Hibbert, DB and Alexander, PW, Flow injection potentiometry by poly(vinyl chloride)-membrane electrodes with substituted azacrown ionophores for the determination of lead(II) and mercury(II) ions, Analytical Chimica Acta, 372, (3) pp. 387-398. ISSN 0003-2670 (1998) [Refereed Article]

DOI: doi:10.1016/S0003-2670(98)00382-1

Abstract

A flow cell with a poly(vinyl chloride) (PVC) neutral-ionophore liquid-membrane ion-selective electrode has been developed for flow injection potentiometry (FIP). The flow system was optimised and five substituted azacrown ethers: 7,16-dithenoyl-1,4,10,13-tetroxa-7,16-diazacyclooctadecane (DTODC), 7,16-di-(2-thiopheneacetyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (DTAODC), 7,16-dithenyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (DTDC), 1,10-dioxa-4,7,13,16-tetraazacyclooctadecane (TC) and 4,7,13,16-tetrathenoyl-1,10-dioxa-4,7,13,16-tetraazacyclooctadecane (TTOTC) synthesised and investigated as the ionophores in Pb2+ (DTAODC, TTOTC) and Hg2+ (DTDC, DTODC, TC, TTOTC) selective electrodes. The short contact times between analyte and ionophore in FIP allow the measurement of a strongly complexing ion such as Hg2+ that saturates the electrodes in batch analysis, or in continuous flow analysis that comes to a steady state. For the mercury-selective electrodes with ionophores with amide functional groups (TTOTC and DTODC) a carrier of 10mM potassium nitrate was found to increase the speed of response and recovery to baseline. The linear calibration range for a DTAODC lead-selective electrode was pPb=2.0 to 5.0 with a slope of 32.5mVdecade-1 and for a TTOTC mercury-selective electrode, pHg=3.0 to 5.5 with a slope of 28.4mVdecade-1. Highly reproducible measurements were obtained (RSD <2%) at a flow rate of 3.0mlmin-1 giving a typical throughput of 40 samples h-1 for Pb2+ and 30 samples h-1 for Hg2+. Copyright (C) 1998 Elsevier Science B.V.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Analytical Chemistry
Research Field:Instrumental Methods (excl. Immunological and Bioassay Methods)
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Chemical Sciences
Author:Alexander, PW (Professor Peter Alexander)
ID Code:14334
Year Published:1998
Web of Science® Times Cited:80
Deposited By:Applied Science
Deposited On:1998-08-01
Last Modified:2011-08-09
Downloads:0

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