Ionic liquids as mobile phase modifiers for the separation of arsenic species in wine by liquid chromatography coupled to atomic fluorescence detection.

ALEXANDER CASTRO GRIJALBA; EMILIANO FIORENTINI; LUIS D MARTINEZ; RODOLFO G. WUILLOUD

Santos, Sao Paulo

Congreso; 5th Iberoamerican Meeting on Ionic Liquids (IMIL 2017); 2017

The application of different ionic liquids (ILs) as modifiers for chromatographic separation and determi-nation of arsenite [As(III)], arsenate [As(V)], dimethylarsonic acid (DMA) and monomethylarsonic acid(MMA) species in wine samples, by reversed-phase high performance liquid chromatography coupled tohydride generation atomic fluorescence spectrometry detection (RP-HPLC-HG-AFS) was studied in thiswork. Several factors influencing the chromatographic separation of the As species, such as pH of themobile phase, buffer solution concentration, buffer type, IL concentration and length of alkyl groups inILs were evaluated. The complete separation of As species was achieved using a C18column in isocraticmode with a mobile phase composed of 0.5% (v/v) 1-octyl-3-methylimidazolium chloride ([C8mim]Cl)and 5% (v/v) methanol at pH 8.5. A multivariate methodology was used to optimize the variables involvedin AFS detection of As species after they were separated by HPLC. The ILs showed remarkable performancefor the separation of As species, which was obtained within 18 min with a resolution higher than 0.83.The limits of detection for As(III), As(V), MMA and DMA were 0.81, 0.89, 0.62 and 1.00 g As L−1. Theproposed method was applied for As speciation analysis in white and red wine samples originated fromdifferent grape varieties.