Schneiderman M A, Sharma A K, Locke D C
Department of Chemistry, Graduate School and Queens College, City University of New York, Flushing 11367.
J Chromatogr Sci. 1988 Sep;26(9):458-62. doi: 10.1093/chromsci/26.9.458.
Menadione (vitamin K3) is extracted from spiked rat chow using supercritical fluid carbon dioxide at 8000 psi and 60 degrees C. Quantitative extraction requires only 20 min. The extraction does not suffer from the problems associated with conventional solvent extraction of lipophilic materials from animal feeds. Menadione is determined in the extract, which does not require further cleanup, using reversed-phase high-performance liquid chromatography (HPLC) with reductive mode electrochemical detection at a silver electrode at -0.75 V vs. calomel. The minimum detectable quantity by the detector is 125 pg of menadione, and the response is linear over at least 4 orders of magnitude; however, the minimum quantity extractable is about 20 micrograms/g of feed. Repetitive extracts of a spiked feed sample over a five-day period show an average recovery of 90.5% with a relative standard deviation of 2.2% at the 1 mg/g level.
使用超临界流体二氧化碳在8000磅力/平方英寸和60摄氏度的条件下从添加了甲萘醌（维生素K3）的大鼠饲料中进行提取。定量提取仅需20分钟。该提取方法不存在与从动物饲料中常规溶剂萃取亲脂性物质相关的问题。提取物中的甲萘醌采用反相高效液相色谱（HPLC）结合在-0.75 V（相对于甘汞电极）的银电极上进行还原模式电化学检测来测定，无需进一步净化。该检测器的最低检测量为125皮克甲萘醌，响应在至少4个数量级内呈线性；然而，可提取的最小量约为20微克/克饲料。在五天时间内对添加了甲萘醌的饲料样品进行重复提取，在1毫克/克水平下，平均回收率为90.5%，相对标准偏差为2.2%。
