Burdette Carolyn Q, Marcus R Kenneth
Clemson University, Biosystems Research Complex, Department of Chemistry, Clemson, SC 29634, USA.
J AOAC Int. 2013 Sep-Oct;96(5):925-32. doi: 10.5740/jaoacint.12-431.
Increased consumption of dietary supplements brings about important requirements of analytical methods to allow accurate and precise measurements of the chemical composition of these botanical materials. Presented here is the isoflavone content in proposed National Institute of Standards and Technology standard reference materials (SRMs) determined by LC-particle beam/electron ionization MS. Botanical materials (soy, red clover, and kudzu) are characterized for the content of a suite of five isoflavones (puerarin, daidzein, genistein, formononetin, and biochanin A). These compounds are of interest due to correlations with certain health benefits. An RP chromatographic separation was first optimized using UV-Vis spectrophotometric detection. The LC output was then introduced to an electron ionization source using a particle beam interface on an Extrel Benchmark MS system. The separation was carried out using a commercial C18 column and a linear gradient using water and methanol (both containing 0.1% trifluoroacetic acid as mobile phases A and B, at a flow rate of 1.0 mL/min over 40 min. LOD values for the isoflavones were determined to be at the ng level. Quantitation was performed using an internal standard (IS) approach with 7-hydroxy-4-chromone as the IS compound. The levels of isoflavones in the botanical products were determined for the proposed SRMs.
膳食补充剂消费量的增加带来了对分析方法的重要要求，以便能够准确、精确地测量这些植物材料的化学成分。本文介绍了通过液相色谱-粒子束/电子电离质谱法测定的美国国家标准与技术研究院拟议标准参考物质（SRM）中的异黄酮含量。对植物材料（大豆、红三叶草和葛根）中一组五种异黄酮（葛根素、大豆苷元、染料木黄酮、芒柄花素和鹰嘴豆芽素A）的含量进行了表征。由于与某些健康益处相关，这些化合物备受关注。首先使用紫外-可见分光光度检测对反相色谱分离进行了优化。然后在Extrel Benchmark MS系统上使用粒子束接口将液相色谱输出引入电子电离源。分离使用商用C18柱和线性梯度进行，流动相A和B分别为水和甲醇（均含有0.1%三氟乙酸），流速为1.0 mL/min，洗脱时间为40分钟。异黄酮的检测限为纳克水平。采用内标法，以7-羟基-4-色酮作为内标化合物进行定量分析。测定了拟议SRM中植物产品的异黄酮含量。
