Determination of Element Contents in Wine Using HR-CS Flame AAS Application Note · contrAA 800

Fast and Reliable Element Contents Analysis in Wine Introduction

Food and drinks are a hot topic of discussion and in the focus of interest with respect to the applicability of certain analytical techniques. Wine consists of a fairly complex matrix including water, sugar, alcohol as well as a great variety of organic and inorganic components. Ethanol especially influences the transport and nebulization properties of the sample due to changes in density and surface tension compared to aqueous standard solutions. The composition of wine is affected by many factors related to a large extent to its specific production area e.g. grape type, soil and climate, culture, wine production process, transport and storage. Wine contains macro-elements with concentrations above 10 mg/L (Na, K, Mg, Ca), micro-elements in the range between 10 mg/L and 10 μg/L (Fe, Cu, Zn, Mn, Pb) and ultramicro-elements with concentrations below 10 μg/L (Cr, As, Cd, Ni). Even though some of these metals such as copper and zinc are essential biometals and lack thereof can lead to serious illness, the majority of them have carcinogenic or toxic effects even at trace levels. Besides consumer health issues, some of these elements may cause precipitation of tartrates and other organic complexes and thus need to be monitored to ensure stability and storability of the wine. For these reasons, it is of great importance to constantly monitor the levels of certain elements.

Atomic absorption spectrometry is the most commonly used technique for metal determination in wines. In fact, the AAS technique is generally little prone to interferences caused by organic compounds due to the high temperatures involved in the atomization step. This application note describes a straightforward and fast analysis of wine using the contrAA 800. Only one dilution factor needed to be applied to measure all of the above listed elements as all absorption lines in the spectral range of 185 to 900 nm can be accessed in the HR-CS AAS. Thus, some of the elements were determined by using secondary wavelengths, while others were evaluated using the primary wavelength.