title: A hybrid sorption - Spectrometric method for determination of synthetic anionic dyes in foodstuffs.
abstract: A sorption-spectrometric method for determination of the anionic synthetic dyes based on their sorption on silica sorbent modified with hexadecyl groups (C16) followed by measuring the diffuse reflectance spectra on the surface of the sorbent has been proposed. Adsorption of sulfonated azo dyes Tartrazine (E102), Sunset Yellow FCF (E110), Ponceau 4R (E124) reaches maximum in acidic medium (1M HCl - pH 1). For the quinophthalone type dye Quinoline Yellow (E104), the adsorption is also maximal in an acidic medium (1M HCl - pH 2). The triphenylmethane dye Fast Green FCF (E143) is absorbed in the wider area of pH (1M HCl - pH 6). Increasing concentration of the dyes in a solution led to the increase in absorption band intensity in diffuse reflectance spectra of the adsorbent, which was used for their direct determination. The proposed method was applied to the determination of dyes in beverages and pharmaceuticals.
authors.affiliation: Analytical Chemistry Division, Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1/3, Moscow 119991, Russia. Electronic address: tikhomirova-tatyana@yandex.ru.
authors.forename: Tatyana I
authors.initials: TI
authors.lastname: Tikhomirova
authors.affiliation: Analytical Chemistry Division, Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1/3, Moscow 119991, Russia.
authors.forename: Gyulselem R
authors.initials: GR
authors.lastname: Ramazanova
authors.affiliation: Analytical Chemistry Division, Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1/3, Moscow 119991, Russia.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Apyari
mesh_terms: D001391:Azo Compounds / Q000032:analysis; D001628:Beverages / Q000032:analysis*; D004396:Coloring Agents / Q000032:analysis*; D005504:Food Analysis / Q000379:methods*; D009282:Naphthalenesulfonates / Q000032:analysis; D013057:Spectrum Analysis / Q000379:methods*; D013645:Tartrazine / Q000032:analysis
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D009282:Naphthalenesulfonates; C005842:6-hydroxy-5-((p- sulfophenyl)azo)-2-naphthalenesulfonic acid disodium salt; D013645:Tartrazine; C576297:ponceau 4R
keywords: Adsorption; Determination; Diasorb-130-C16; Diffuse reflectance spectroscopy; Fast Green FCF (PubChem CID: 16887); Food dye; Hydrochloric acid (PubChem CID: 313); Ponceau 4R (PubChem CID: 9570119); Quinoline Yellow WS (PubChem CID: 24671); Separation; Sodium chloride (PubChem CID: 5234); Sodium hydroxide (PubChem CID: 14798); Sunset Yellow FCF (PubChem CID: 6850717); Tartrazine (PubChem CID: 164825)