Overcoming absorption effects in the determination of light elements in beverages by total‐reflection X‐ray spectrometry

Abstract

AbstractTotal‐reflection X‐ray fluorescence spectrometry (TXRF) is one of the analytical methods for the rapid and cost‐efficient multielemental analysis of solid and liquid objects. However, the method has some issues in the quantitative analysis due to the possible matrix effects. Since alcoholic and nonalcoholic beverages contain a high percentage of carbohydrates (especially sucrose), ethanol, and other organic compounds, the issues of matrix effects are significant and should be studied. Basically, absorption effects appear in the determination of “light” elements as P, S, K, and Ca. This article showed the capabilities of TXRF applying to the determination of “light” elements in alcoholic and nonalcoholic beverages using two sample preparation techniques: direct analysis and acid digestion. Due to the lack of certified reference materials for beverages, the model solutions with a matrix of 5% sugar in water were prepared according to the developed experimental design. The absorption effects that influenced the accuracy of TXRF analysis of beverages were demonstrated and quantitatively estimated. The quantification procedures for direct analysis of beverages were optimized using external calibration. The real samples of wine, beer, juice, and soft drink were analyzed using the offered approaches, and results of TXRF were compared to inductively coupled plasma mass spectrometry.