Chromium(III) ion selective electrode based on glyoxal bis(2- hydroxyanil) M.B. Gholivand *, F. Sharifpour Department of Chemistry, Faculty of Science, University of Razi, Kermanshah, Iran Received 26 June 2002; received in revised form 22 January 2003; accepted 11 February 2003 Abstract A poly(vinyl chloride) membrane based on glyoxal bis(2-hydroxyanil) as membrane carrier was prepared and investigated as a Cr(III)-selective electrode. The electrode has a linear dynamic range of 3.0 /10 6 /1.0 /10 2 mol l 1 , with a Nernstian slope of 19.89/0.5 mV per decade and a detection limit of 6.3 /10 7 mol l 1 . It has a fast response time of B/20 s and can be used for at least 3 months without any considerable divergence in potential. The proposed electrode revealed good sensitivities for Cr(III) over a wide variety of metal ions and could be used in a pH range of 2.7 /6.5. Above all, the membrane sensor has been used very successfully for the analysis of some food materials and alloys for the determination of Cr(III) ion. # 2003 Elsevier Science B.V. All rights reserved. Keywords: Ion-selective electrode; Glyoxal bis(2-hydroxyanil); Chromium (III) ion selective electrode 1. Introduction The increasing use of ion sensors in the fields of environmental, agricultural and medicinal analysis is stimulating analytical chemists to develop new sensors for the fast, accurate, reproducible and selective determination of various species. In the past few decades, considerable efforts have led to the development of selective sensors for alkali, alkaline earth and heavy metals. Among heavy metals, trivalent metals have received less attention in spite of their widespread occurrence in food products, sea and fresh water, plants and animals [1]. A literature survey revealed that a large number of ISEs based on PVC membrane were reported for many inorganic ions [2], but very little was published on PVC-based trivalent ions. The first report on Cr(III) was in 1980 [3] in which study a PVC based chromium-wire electrode was made by incorporating (Aliquat 336S  /Cr(SCN) 4  ) ion- pair, and the electrode gave a fully response in the Cr(SCN) 4  concentration range of 10 5 /10 2 mol l 1 and has the Nernstian slop of 58 mV per pCr. In 1987 [4] a Cr(III) selective electrode with * Corresponding author. Tel.: /98-831-422-3306; fax: /98- 831-422-8439. E-mail addresses: mbgh@razi.ac.ir, mbgholivand@yahoo.com (M.B. Gholivand). Talanta 60 (2003) 707 /713 www.elsevier.com/locate/talanta 0039-9140/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0039-9140(03)00130-9