A reliable method of quantification of trace copper in beverages with and without alcohol by spectrophotometry after cloud point extraction

Abstract

A new cloud point extraction (CPE) method was developed for the separation and preconcentration of copper (II) prior to spectrophotometric analysis. For this purpose, 1-(2,4-dimethylphenyl) azonapthalen-2-ol (Sudan II) was used as a chelating agent and the solution pH was adjusted to 10.0 with borate buffer. Polyethylene glycol tert-octylphenyl ether (Triton X-114) was used as an extracting agent in the presence of sodium dodecylsulphate (SDS). After phase separation, based on the cloud point of the mixture, the surfactant-rich phase was diluted with acetone, and the enriched analyte was spectrophotometrically determined at 537 nm. The variables affecting CPE efficiency were optimized. The calibration curve was linear within the range 0.285-20 µg L −1 with a detection limit of 0.085 µg L −1. The method was successfully applied to the quantification of copper in different beverage samples.

Oxidation and Complexation-Based Spectrophotometric Methods for Sensitive Determination of Tartrazine E102 in Some Commercial Food Samples

“…A reduction process, which corresponds to a spontaneous auto−reduction of the Cu 2+ into Cu + , was observed in cases of complexation of Cu 2+ ions with sudan(I) [31] and sudan(II) [32]. Because of these features of sudan dyes, tartrazine is considered as chromogenic chelating and redox sensitive agent reacting with copper(II) to form Cu + -Tz complex under optimum conditions.…”

“…Under optimum conditions the intraday precision was carried out for our procedures through replicate analysis (n = 5) for Tz corresponding to 32 (method II). The interday precision was also evaluated through replicate analysis of the standard Tz for three consecutive days at the same concentration levels as in within day precision.…”

Utilization of Aluminon for Determination of Ultra-trace Levels of Copper in Environmental, Biological, and Water Samples via Cloud Point Extraction Coupled with Spectrophotometry

“…High doses of copper result in a series of systematic toxic effects such as hemolysis, hepatic neurosis, gastrointestinal bleeding, oliguria azotemia, hemoglobinuria, hematuria, proteinuria, hypertension, tachycardia, convulsions, and coma [9]. Humans are commonly exposed to copper from drinking water, breathing air, foods or through having skin contact with copper, particles attached to copper or copper-containing compounds [10].…”