Wroclaw University of Science and Technology, Faculty of Chemistry, Division of Analytical Chemistry and Chemical Metallurgy, Wybrzeze Stanislawa Wyspianskiego 27, 50370 Wroclaw, Poland.
Food Chem. 2018 Oct 15;263:171-179. doi: 10.1016/j.foodchem.2018.04.127. Epub 2018 May 2.
A simple method of simultaneous determination of aluminum (Al), barium (Ba), calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), strontium (Sr) and zinc (Zn) in brews of ground and soluble coffees was proposed. It relied on acidification of brews with HNO to 1.3 mol L and their analysis by inductively coupled plasma optical emission spectrometry. Precision of 0.1-9% and detection limits from 0.07 ng mL (Sr) to 3 ng mL (Ni) were achieved. Trueness of the method was verified by comparison of results with those achieved with wet digestion and by the recovery study, and was better than 5%. Additionally, chemical fractionation by tandem solid phase extraction with reverse-phase and strong cation-exchange extraction tubes was carried out. Differences in chemical fractionation patterns, particularly the residual fraction, was useful for differentiation of ground and soluble coffees by analysis of variance, principle component analysis and hierarchical clustering analysis.
提出了一种简单的方法，用于同时测定研磨咖啡和速溶咖啡浸提液中的铝（Al）、钡（Ba）、钙（Ca）、铜（Cu）、铁（Fe）、镁（Mg）、锰（Mn）、镍（Ni）、锶（Sr）和锌（Zn）。该方法依赖于将浸提液用 HNO 酸化至 1.3 mol·L，然后用电感耦合等离子体发射光谱法进行分析。该方法的精密度为 0.1-9%，检出限为 0.07ng·mL（Sr）至 3ng·mL（Ni）。方法的准确性通过与湿法消解和回收率研究的结果进行比较得到验证，均优于 5%。此外，还进行了串联固相萃取的化学形态分析，采用反相和强阳离子交换萃取管。通过方差分析、主成分分析和层次聚类分析，对化学形态分析结果，特别是残留形态的差异进行分析，有助于区分研磨咖啡和速溶咖啡。
