Isotope ratio mass spectrometry coupled to liquid and gas chromatography for wine ethanol characterization

Abstract

Two new procedures for wine ethanol 13 C/ 12 C isotope ratio determination, using high-performance liquid chromatography and gas chromatography isotope ratio mass spectrometry (HPLC/IRMS and GC/IRMS), have been developed to improve isotopic methods dedicated to the study of wine authenticity. Parameters influencing separation of ethanol from wine matrix such as column, temperature, mobile phase, flow rates and injection mode were investigated. Twenty-three wine samples from various origins were analyzed for validation of the procedures. The analytical precision was better than 0.15%, and no significant isotopic fractionation was observed employing both separative techniques coupled to IRMS. No significant differences and a very strong correlation (r ¼ 0.99) were observed between the 13 C/ 12 C ratios obtained by the official method (elemental analyzer/isotope ratio mass spectrometry) and the proposed new methodology. The potential advantages of the developed methods over the traditional one are speed (reducing time required from hours to minutes) and simplicity. In addition, these are the first isotopic methods that allow 13 C/ 12 C determination directly from a liquid sample with no previous ethanol isolation, overcoming technical difficulties associated with sample treatment.

Strong anion exchange liquid chromatographic separation of protein amino acids for natural 13C‐abundance determination by isotope ratio mass spectrometry

“…[3][4][5][6] The principal disadvantage of derivatisation is that additional carbon atoms are added which attenuate the 13 C signal and may introduce isotopic fractionation, resulting in error propagation in determining 13 C abundance by gas chromatography/combustion/IRMS (GC/C/IRMS), where derivatisation of amino acids is mandatory. [7] Complete chromatographic resolution of analytes prior to non-fractionating C oxidation to CO 2 , and subsequent introduction into an IRMS instrument is key to achieving isotope ratio measurement precision and accuracy.…”

“…[7] Complete chromatographic resolution of analytes prior to non-fractionating C oxidation to CO 2 , and subsequent introduction into an IRMS instrument is key to achieving isotope ratio measurement precision and accuracy. To date, various forms of cation exchange chromatography (two-dimensional (2D), [3,8] strong cation exchange [4] and mixed-mode [5,6] ) have been reported for 13 C amino acid determination by LC/IRMS. The utility of SAX chromatography coupled with IRMS has been reported for the analysis of sugars; [2,9] however, it has not been explored for amino acid analysis, although robust protocols have been developed for amino acid separation by strong anion chromatography.…”

“…Recent developments in liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) interface design [1,2] have heralded the precise determination of the d 13 C values of amino acids at natural abundance without the need for prior derivatisation. [3][4][5][6] The principal disadvantage of derivatisation is that additional carbon atoms are added which attenuate the 13 C signal and may introduce isotopic fractionation, resulting in error propagation in determining 13 C abundance by gas chromatography/combustion/IRMS (GC/C/IRMS), where derivatisation of amino acids is mandatory.…”

“…The utility of SAX chromatography coupled with IRMS has been reported for the analysis of sugars; [2,9] however, it has not been explored for amino acid analysis, although robust protocols have been developed for amino acid separation by strong anion chromatography. [10][11][12] A brief survey of amino acid separations in the liquid phase shows that 2D chromatography, where a strong cation exchange column was placed ahead of a reversed-phase C30 column, separated 11 of the 15 amino acids analysed following acid hydrolysis and the d 13 C precision of several amino acids was about 0.3%. [3] Similarly, use of a reversed-phase column with ion-pairing reagents separated all 15 amino acids hydrolysed from bone collagen.…”

Grape wines, problems of their quality and regional origin evaluation

“…Для дости-жения этих целей существенно расширяется круг определяемых компонентов, разрабатываются и совершенствуются методики их детектирования с применением современных инструментальных методов анализа [102]. Качество и подлинность вин устанавливают по качественному и количе-ственному содержанию в винах биогенных аминов [103][104][105], аминокислот [26,27,106], органических кислот [107][108][109], полиолов [100] альдегидов [110,111] и ароматических кислот [111], фенольных ве-ществ [112,113], летучих соединений [87], углево-дов [107], пентоз [114], подсластителей [107,115], консервантов [115], глицерина [116,117] [120][121][122][123][124][125][126]. По заявлениям ряда вышеперечисленных авторов, в некоторых случаях достигается уровень идентификации вин свыше 90 %.…”