Eibisch Mandy, Popkova Yulia, Süß Rosmarie, Schiller Jürgen, Dannenberger Dirk
Medical Faculty, Institute of Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, 04107, Leipzig, Germany.
Anal Bioanal Chem. 2014 Nov;406(28):7401-5. doi: 10.1007/s00216-014-8162-4. Epub 2014 Sep 17.
The quantitative determination of the total free fatty acids (FFAs) is an important analytical task because FFAs exhibit important physiological effects and are also relevant in many other fields, for instance, in food research. Our aim was to investigate whether a commercially available enzymatic test kit developed for the determination of FFAs in human serum is also suitable to determine different physiological and nonphysiological FFAs and to which extent the impact on the sensitivities (i.e., the accuracy by which a given FFA can be determined) differ. It will be shown that the chain length as well as the double bond content has a significant impact on the sensitivity by which a given FFA can be determined. For instance, palmitic acid (16:0) is determined with an approximately 20 times higher sensitivity in comparison to docosahexaenoic acid (22:6n-3). All data were obtained by measuring the concentrations of the FFAs by gas chromatography, and selected FFAs were also determined in a complex matrix of human serum. It is concluded that this kit is not useful if major alterations of the FFA composition of a complex mixture are expected because the individual FFAs are not detected with the same sensitivities: the concentrations of polyunsaturated FFA determined by this kit are wrong.
总游离脂肪酸（FFA）的定量测定是一项重要的分析任务，因为游离脂肪酸具有重要的生理作用，并且在许多其他领域也具有相关性，例如在食品研究中。我们的目的是研究一种为测定人血清中游离脂肪酸而开发的商用酶测试试剂盒是否也适用于测定不同的生理性和非生理性游离脂肪酸，以及对灵敏度（即测定给定游离脂肪酸的准确度）的影响在何种程度上存在差异。结果表明，链长以及双键含量对测定给定游离脂肪酸的灵敏度有显著影响。例如，与二十二碳六烯酸（22:6n-3）相比，棕榈酸（16:0）的测定灵敏度大约高20倍。所有数据均通过气相色谱法测量游离脂肪酸的浓度获得，并且还在人血清的复杂基质中测定了选定的游离脂肪酸。得出的结论是，如果预期复杂混合物的游离脂肪酸组成会发生重大变化，那么该试剂盒就没有用，因为各个游离脂肪酸的检测灵敏度不同：用该试剂盒测定的多不饱和游离脂肪酸的浓度是错误的。
