Aureliano Amati

Analysis of wine phenolics by high-performance liquid chromatography using a monolithic type column

A HPLC method involving direct injection was developed to determine phenolic compounds in wine. The separation was carried out on an RP C18 monolithic column using a binary gradient elution and diode array detection. In this way 17 monomeric compounds of different phenolic groups (hydroxybenzoic acids, hydroxycinnamic acids, hydroxycinnamyltartaric acids, flavanol, flavonol and stilbenes) could be separated and quantified in a single run and in a very short time.

AN IMPROVED HPLC METHOD FOR THE ANALYSIS OF ORGANIC ACIDS, CARBOHYDRATES, AND ALCOHOLS IN GRAPE MUSTS AND WINES

An improved high performance liquid chromatography (HPLC) method for the analysis of the main organic compounds in musts and wines is presented. A column packed with hydrogen sulfonated divinyl benzene-styrene copolymer and two detectors connected in series were used (UV at 210 nm and RI, respectively). The addition of acetonitrile (6%) to the mobile phase (0.045N H2SO4) allowed the simultaneous separation and quantification of several organic acids, glucose, fructose, glycerol, and ethanol. Direct injection and sample clean-up with a SAX cartridge was tested and compared. The SAX fractionation gave satisfactory results, however the direct injection of diluted wine (1:20) provided the best precision (CV ≤ 2.1%) and accuracy of analysis. Statistical analysis (paired t-test) disclosed significant differences only for glucose, fructose, α-ketoglutaric, and pyruvic acid. The role of column temperature for the analysis of vitamin C (ascorbic acid) was also investigated. Vitamin C underwent thermal degradation during analysis with column temperature ≥ 30°C.

SIMULTANEOUS DETERMINATION OF ORGANIC ACIDS, SUGARS, AND ALCOHOLS IN MUSTS AND WINES BY AN IMPROVED ION-EXCLUSION HPLC METHOD

ABSTRACT An HPLC method for the simultaneous quantification of the main carboxylic acids (including citric, tartaric, malic, shikimic, succinic, lactic, fumaric, and acetic acids), sugars (glucose and fructose), and alcohols (glycerol and ethanol) of musts and wine is proposed. Using a cation exchange column, improved separation of coeluting compounds (e.g., fructose vs. malic acid and succinic vs. shikimic acid) was achieved by moderate addition of tetarhydrofuran (THF) (4%) and n-propyl alcohol (n-PA) (5%) as organic modifier in the mobile phase. A factorial experiment was carried out for optimize acidity and temperature of elution. The method showed good linearity and precision and, as an application, was successfully applied to a must and a wine.