Faculty of Science, Department of Analytical Chemistry, Charles University, Hlavova 2030/8, 128 40, Prague 2, Czech Republic; Chemistry Faculty, Department of Analytical Chemistry, Belarusian State University, Leningradskaya 14, 220050, Minsk, Belarus; Institute for Nuclear Problems of Belarusian State University, 220006, Bobruyskaya Str., 11, Minsk, Belarus.
Faculty of Science, Department of Analytical Chemistry, Charles University, Hlavova 2030/8, 128 40, Prague 2, Czech Republic.
Talanta. 2022 Aug 15;246:123518. doi: 10.1016/j.talanta.2022.123518. Epub 2022 Apr 30.
This paper focuses on the evaluation of variation of relative response factors (RRFs) obtained by two internal standard (IS) methods that are used to control the quality of alcoholic products. A standard IS method using 1-pentanol was compared with an "Ethanol as IS" method. The variation of RRF values for both methods was determined using standard solutions based on 20, 40 and 96% ethanol-water matrices. For this purpose, solutions of the ten most abundant volatile compounds were analysed at four different concentrations (250, 500, 1000 and 5000 mg L absolute alcohol, AA) within these matrices. Each solution was measured four times by gas chromatography-mass spectrometry (GC-MS) in single ion monitoring (SIM) mode under repeatability conditions. Our results showed that for the 40% and 96% matrices, the ethanol and standard IS methods showed similar relative standard deviations (RSDs) variation of no more than 2% within the 250-1000 mg L AA volatile compounds concentration range. For the 20% matrix as well as for the 250-5000 mg L AA concentration range the resulting variation in calibration factors reaches 10% for both methods. As for the whole range of 20-96% alcohol by volume (ABV) and 250-5000 mg L AA volatile concentration range, the resultant RRFs for the standard IS method (8% RSD) were more stable than those for the ethanol IS method (almost 40% RSD). Nonlinearity of the signal-to-amount dependence was also assessed with respect to the injection and detection processes.
本文重点评估了两种内标（IS）方法得到的相对响应因子（RRF）的变化，这两种方法用于控制酒精产品的质量。将使用 1-戊醇的标准 IS 方法与“乙醇作为 IS”方法进行比较。使用基于 20%、40%和 96%乙醇-水基质的标准溶液来确定这两种方法的 RRF 值变化。为此，在这些基质中，分析了 20 种最丰富挥发性化合物的溶液，浓度分别为 250、500、1000 和 5000mg/L 绝对酒精（AA）。每种溶液在重复性条件下通过气相色谱-质谱（GC-MS）在单离子监测（SIM）模式下测量四次。我们的结果表明，对于 40%和 96%的基质，乙醇和标准 IS 方法在 250-1000mg/L AA 挥发性化合物浓度范围内，相对标准偏差（RSD）的变化不超过 2%。对于 20%的基质以及 250-5000mg/L AA 浓度范围，两种方法的校准因子变化均达到 10%。对于整个 20-96%体积酒精（ABV）和 250-5000mg/L AA 挥发性浓度范围，标准 IS 方法（8%RSD）的 RRF 比乙醇 IS 方法（近 40%RSD）更稳定。还评估了信号量依赖性的非线性与进样和检测过程有关。
