Automatic determination of quinine by atomic absorption spectrometry

• Published in: Microchemical journal Vol. 65; no. 1; pp. 81 - 86
• Main Authors: Yebra, M.C, Cespón, R.M
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier B.V 01.07.2000; Elsevier
• Subjects: Analytical chemistry; Biological and medical sciences; Chemistry; Continuous precipitation; Exact sciences and technology; Flame atomic absorption spectrometry; Flow injection; Food industries; Fundamental and applied biological sciences. Psychology; Non alcoholic beverage industries and mineral waters; Quinine; Soft drinks; Spectrometric and optical methods; Continuous precipitation; Flame atomic absorption spectrometry; Quinine; Flow injection; Soft drinks; Chemical analysis; Anionic complex; Transition metal Complexes; Flame spectrometry; Chemical enrichment; Alkaloid; Ionic association; Indirect method; Cadmium Complexes; Quality control; Soft drink; Iodo complex; Beverage industry; Quantitative analysis; Atomic absorption spectrometry
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/S0026-265X(00)00034-5

A flow injection method for the indirect determination of quinine, based on the precipitation of an ion-association species formed between the quinine and Marmé reagent (CdI 4 2−) is reported. The precipitate is obtained by injecting the Marmé reagent into a carrier stream containing the quinine, and is then retained on a filter, the filtrate then being directly aspirated into an atomic absorption spectrometer to determine the unprecipitated cadmium. The calibration graph was linear over the range 5–110 μg ml −1 quinine, and the relative standard deviation for determination of 40 μg ml −1 quinine was 2.1%. The 3σ detection limit was 2 μg ml −1. No other compounds normally found in soft drinks had any effect on the quinine determination. The accuracy of the method was checked by means of the well established fluorimetric method.