Chu T Y, Chang C H, Liao Y C, Chen Y C
Department of Chemical Engineering, Hsiuping Institute of Technology, Tali, Taichung 412, Taiwan.
Talanta. 2001 Jul 6;54(6):1163-71. doi: 10.1016/s0039-9140(01)00392-7.
A rapid method for the derivatization of phenolic antioxidants using microwave irradiation has been developed. Six antioxidatively active phenolic components of wines and fruits, namely gallic acid, gentisic acid, vanillic acid, caffeic acid, ferulic acid and p-coumaric acid were used in the model study. The solution of phenolic acids was evaporated to dryness on a rotary evaporator followed by further drying under microwave irradiation (600 W, 30 s). The resultant residue was dissolved in pyridene and treated with bis(trimethylsilyl)acetamide while irradiated by microwave using high power for 30 s. Controlled reaction was carried out employing bis(trimethylsilyl)trifluoroacetamide under conventional heating for 30 min. The trimethylsilyl derivatives were identified and quantified on a gas chromatography/mass selective detector. The mass spectral fragmentation patterns of the derivatives obtained by microwave irradiation were identical to those prepared by heating. The yields of microwave-assisted silylation were comparable to those from conventional heating. The rsd were less than 8% for six replicates. The linearity in wine matrix was nearly perfect. This method is a useful protocol to examine the phenolic constituents in wines and agricultural products.
已开发出一种利用微波辐射对酚类抗氧化剂进行衍生化的快速方法。在模型研究中使用了葡萄酒和水果中的六种具有抗氧化活性的酚类成分，即没食子酸、龙胆酸、香草酸、咖啡酸、阿魏酸和对香豆酸。将酚酸溶液在旋转蒸发仪上蒸发至干，然后在微波辐射（600W，30s）下进一步干燥。将所得残渣溶于吡啶，并用双（三甲基硅基）乙酰胺处理，同时在高功率微波辐射下照射30s。采用双（三甲基硅基）三氟乙酰胺在常规加热下进行30分钟的可控反应。在气相色谱/质量选择检测器上对三甲基硅基衍生物进行鉴定和定量。通过微波辐射得到的衍生物的质谱裂解模式与加热制备的衍生物相同。微波辅助硅烷化的产率与常规加热的产率相当。六次重复的相对标准偏差小于8%。在葡萄酒基质中的线性几乎完美。该方法是检测葡萄酒和农产品中酚类成分的有用方案。
