Irakli Maria N, Samanidou Victoria F, Biliaderis Costas G, Papadoyannis Ioannis N
Cereal Institute, National Agricultural Research Foundation, P.O. Box 60411, Thessaloniki 57 001, Greece.
Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University, Thessaloniki 54 124, Greece.
Food Chem. 2012 Oct 1;134(3):1624-32. doi: 10.1016/j.foodchem.2012.03.046. Epub 2012 Mar 19.
Whole cereal grains are a good source of phenolic acids associated with reduced risk of chronic diseases. This paper reports the development and validation of a high-performance liquid chromatography-diode array detection (HPLC-DAD) method for the determination of phenolic acids in cereals in either free or bound form. Extraction of free phenolic acids and clean-up was performed by an optimised solid-phase extraction (SPE) protocol on Oasis HLB cartridges using aqueous methanol as eluant. The mean recovery of analytes ranged between 84% and 106%. Bound phenolic acids were extracted using alkaline hydrolysis with mean recoveries of 80-95%, except for gallic acid, caffeic acid and protocatechuic acid. Both free and bound phenolic extracts were separated on a Nucleosil 100 C18 column, 5 μm (250 mm × 4.6 mm) thermostated at 30 °C, using a linear gradient elution system consisting of 1% (v/v) acetic acid in methanol. Method validation was performed by means of linearity, accuracy, intra-day and inter-day precision and sensitivity. Detection limits ranged between 0.13 and 0.18 μg/g. The method was applied to the analysis of free and bound phenolic acids contents in durum wheat, bread wheat, barley, oat, rice, rye, corn and triticale.
全谷物是酚酸的良好来源，与降低慢性病风险相关。本文报道了一种用于测定谷物中游离或结合态酚酸的高效液相色谱 - 二极管阵列检测（HPLC - DAD）方法的开发与验证。游离酚酸的提取和净化通过优化的固相萃取（SPE）方案在Oasis HLB柱上进行，使用甲醇水溶液作为洗脱剂。分析物的平均回收率在84%至106%之间。结合态酚酸采用碱性水解法提取，除没食子酸、咖啡酸和原儿茶酸外，平均回收率为80 - 95%。游离和结合态酚酸提取物均在一根粒径为5μm、规格为250 mm×4.6 mm的Nucleosil 100 C18柱上进行分离，柱温30℃，使用由甲醇中1%（v/v）乙酸组成的线性梯度洗脱系统。通过线性、准确度、日内和日间精密度以及灵敏度进行方法验证。检测限在0.13至0.18μg/g之间。该方法应用于硬粒小麦、面包小麦、大麦、燕麦、水稻、黑麦、玉米和小黑麦中游离和结合态酚酸含量的分析。
