Sensitive determination of impurities in samples of vodka by gas chromatography with flame-ionization detection

<p>Vodka is one of the most popular alcoholic drinks around the world. Adulteration of vodkas lead to many negative consequences. A number of analytical methods covers a wide range of analytes and allows detection of adulterated alcoholic beverages, however, most of these methods are very labor and time consuming or require expensive analytical instrumentation. The simplest and thus most popular method is based on direct analysis by gas chromatography (GC) with flame-ionization detection (FID). The main drawback of this method for discovery of adulterated vodka samples is insufficient sensitivity. The aim of this study was to increase sensitivity of the method for determination of key vodka impurities. Optimized parameters included split ratio 10:1, inlet temperature &gt;120 °C, initial oven temperature 60 °C, flow rates of make-up gas, air and hydrogen 50, 400 and 40 mL/min, respectively. Obtained calibration plots are linear in the concentration range between 1 and 1000 mg/L with approximation coefficients R²&gt;0.99. Compared to a standard method, slope factors are about 4 times higher when optimized method is used proving its higher sensitivity.</p>