HPLC method validation and application for organic acid analysis in wine after solid-phase extraction

Abstract

A solid-phase extraction method followed by reverse phase high-performance liquid chromatography (RP-HPLC) was optimized and validated for the quantitative determination of tartaric, malic, shikimic, lactic, citric and succinic acids in wine. Solid-phase extraction was carried out with C18 cartridges and extraction recoveries for all acids ranging from 98.3 to 103% were obtained. HPLC separation was performed with isocratic elution on a LiChrosorb RP-18 column (250 × 4.6 mm I.D., 5 µm) protected with the appropriate guard column. The mobile phase was a 5 mM solution of H3PO4 with pH 2.1 at a flow rate of 1 ml/min. Detection of the organic acids was performed at 210 nm. The developed method was validated by checking its linearity, limit of detection (LOD), limit of quantification (LOQ), precision and recovery. The method was applied to the analysis of organic acids in Macedonian red and white wines.Keywords: wine; organic acids; separation; HPLC; validation ВАЛИДАЦИЈА И ПРИМЕНА НА HPLC ЗА АНАЛИЗА НА ОРГАНСКИ КИСЕЛИНИ ВО ВИНО ПО ЦВРСТО-ФАЗНА ЕКСТРАКЦИЈАОптимизиран и валидиран е метод за квантитативна анализа на винска, јаболкова, шикимска, млечна, лимонска и килибарна киселина во вино со цврсто-фазна екстракција следена со реверзно-фазна високо ефикасна течна хроматографија (RP-HPLC). Цврсто-фазната екстракција е изведена со колони C18 и добиениот аналитички принос за сите киселини се движи од 98,3 до 103%. Разделувањето со HPLC е извршено со изократско елуирање на LiChrosorb-ова колона RP-18 (250 × 4,6 mm I.D., 5 µm) користејќи соодветна претколона. Мобилната фаза којашто е употребена за елуирање е раствор од H3PO4 со концентрација 5 mM и pH 2,1 при проток од 1 ml/min. Детекцијата на органските киселини е извршена со следење на апсорбанцата на 210 nm. Развиениот метод е валидиран со проверка на неговата линеарност, осетливост, граница на детекција (LOD), граница на квантификација (LOQ), аналитички принос и прецизност. Методот потоа е применет за анализа на органски киселини во македонски црвени и бели вина.

Elemental composition as a tool for the assessment of type, seasonal variability, and geographical origin of wine and its contribution to daily elemental intake

“…The highest concentration of Na (mean 23.0 AE 11.7 mg L À1 ) ( 35 The content of trace elements (Be, Co, Sb, and Se) found in Serbian wines agreed with literature data (Table S3 †). 5,16,30,33 Regarding the content of toxic elements (As, Cd, and Pb) (Tables 1-3), the As content was higher than in published data (Table S3 †) 16,27,30,31,36 while the Pb content was lower than that in Czech 30 and Romanian 33 wines. The average content of Cd was slightly higher than in wines from Serbia's neighbouring countries Croatia 16 and Macedonia.…”

“…The average content of Cd was slightly higher than in wines from Serbia's neighbouring countries Croatia 16 and Macedonia. 5 Only one sample contained elevated concentrations of this element. Analysing data from Table S3, † Serbian wines were concluded to contain higher amounts of essential elements (Cu, Mn, and Zn) and major elements (Ca and Mg) in comparison to Belgian 32 or Argentinian 31 wines.…”

“…16 The high impact of Cu on differentiation could be the result of its accumulation in soil aer the application of Bordeaux mixture or other copper-based fungicides or the use of equipment based on this metal. 5,15,29 Also, the increase of Cu concentration may occur due to adding copper salts to remove H 2 S.…”

“…The exogenous elemental content (Al, Cd, Cr, Cu, Fe, and Zn) depends on external impurities during the growth of grapes and vinicultural and winemaking practices. 1,5,6 Anthropogenic factors, such as application of pesticides, fungicides, and fertilisers during the growing season, can lead to an increase in Cd, Cu, Mn, As, and Zn in the resulting wine. The presence of Pb in wines can originate from sources like traffic, fertilisers, vessels, and pumps used during vinication.…”

“…9 Thus, determination of the elemental concentrations in wine allows calculation of their daily dietary intake from wine, which is of particular importance for toxic elements. Various instrumental techniques have been used to classify wine variety such as infrared spectroscopy (IR), 10 nuclear magnetic resonance (NMR), 11 gas chromatography (GC), 12 highperformance liquid chromatography (HPLC), 13,14 inductively coupled plasma optical emission spectrometry (ICP OES), 5,15 and inductively coupled plasma mass spectrometry (ICP MS). 4,16 The advantages of ICP-based techniques for the determination of trace elements are numerous: high sensitivity, a wide range of linearity, and simultaneous multielement analysis.…”