Ion-selective electrode for potentiometric determination of aluminium(III) in fluoride medium

Quimica nova

Piccin, Evandro¹  Fatibello-Filho, Orlando¹  Ramos, Luiz Antonio² 

[1] Universidade Federal de São Carlos, São Carlos;Universidade de São Paulo, São Carlos

关键词: aluminium(III) determination;    ion-selective electrode;    potentiometry.;   

DOI  :  10.1590/S0100-40422004000600012

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

The constructionand analytical evaluation of a coated graphite Al(III) ion-selective electrode,based on the ionic pair formed between the Al(F)n3-n anionand tricaprylylmethylammonium cation (Aliquat 336S) incorporated on a poly(vinylchloride)(PVC) matrix membrane are described. A thin membrane film of this ionic pairand dibutylphthalate (DBPh) in PVC was deposited directly on a cylindric graphiterod (2 cm length x 0.5 cm diameter) attached to the end of a glass tube usingepoxy resin. The membrane solution was prepared by dissolving 40% (m/m) of PVCin 10 mL of tetrahydrofuran following addition of 45% (m/m) of DBPh and 15%(m/m) of the ionic pair. The effect of membrane composition, fluoride concentration,and several concomitants as potential interferences on the electrode responsewere investigated. The aluminium(III) ion-selective electrode showed a linearresponse ranging from 1.4 x 10-4 to 1.0 x 10-2 mol L-1,a detection limit of 4.0 x 10-5 mol L-1, a slope of -54.3±0.2mVdec-1 and a lifetime of more than 1 year (over 3000 determinationsfor each membrane). The slope indicates that the ion-selective electrode respondspreferentially to the Al(F)4- species. Application ofthis electrode for the aluminium(III) determination in stomach anti-acid samplesis reported.

【 授权许可】

CC BY