ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A simple cloud point extraction-spectrophotometric method for total vanadium determination using 4-(2-thiazolylazo)resorcinol and H₂O₂

Fatma Genç, Nikolina P. Milcheva, Danail G. Hristov, and Kiril B. Gavazov

Faculty of Pharmacy, Yeni Yüzyıl Üniversitesi, Istanbul, Turkey

E-mail: kgavazov@abv.bg

Received: 7 September 2019  Accepted: 17 December 2019

Abstract:

A cloud point extraction-chromogenic system for vanadium determination containing 4-(2-thiazolylazo)resorcinol (TAR), H₂O₂, H₂SO₄, and Triton X-100 was investigated. Optimal conditions for the formation and extraction of a 1:2:1 (V^V:O₂²⁻:TAR) ternary complex with an absorption maximum at 569 nm were found: concentration of TAR (4 × 10⁻⁵ mol dm⁻³), concentration of H₂O₂ (1.2 × 10⁻⁴ mol dm⁻³), pH (ca 2), mass fraction of the surfactant (3.6%), and incubation time (40 min). The molar absorptivity (ε₅₆₉), Sandell’s sensitivity (SS), limit of detection (LOD) and linear working range (LWR) were 7.4 × 10⁴ dm³ mol⁻¹ cm⁻¹, 0.69 ng cm⁻², 1.7 ng cm⁻³ and 6–510 ng cm⁻³, respectively. The effect of foreign ions was studied. The developed procedure was applied for the spectrophotometric determination of the total vanadium content in spent silica-supported catalysts and a vanadium-containing dietary supplement.

Graphic Abstract:

Keywords: Cloud point extraction; Vanadium; 4-(2-Thiazolylazo)resorcinol; Hydrogen peroxide; Spectrophotometric determination

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-019-01038-8

Chemical Papers 74 (6) 1891–1901 (2020)