Schimpf Karen J, Butler Thompson Linda D, Pan Shang-Jing
Abbott Laboratories, 3300 Stelzer Rd, Columbus, OH 43219.
J AOAC Int. 2018 Jul 25. doi: 10.5740/jaoacint.18-0155.
A multilaboratory study was completed with AOAC INTERNATIONAL First Action 2015.09, "Determination of and Total () Vitamin K in Infant, Pediatric, and Adult Nutritionals by HPLC with Post Column Reduction and Fluorescence Detection." Eight laboratories from six countries participated in the multilaboratory study. Each laboratory analyzed 19 infant, pediatric, and adult nutritionals in duplicate. The product matrixes analyzed included milk, soy, partially hydrolyzed milk, partially hydrolyzed soy, and elemental-based infant formula powders; milk-based infant formula ready-to-feed liquids; pediatric powders; adult low- and high-fat powders; and high-protein ready-to-drink nutritionals. Vitamin K was extracted from product matrixes with isooctane after precipitation of proteins and the release of lipids with methanol. Prepared samples were injected onto a silica HPLC column in which and vitamin K were separated with an isooctane-isopropanol mobile phase. The column eluent was mixed with a dilute ethanolic solution of zinc chloride, sodium acetate, and acetic acid, and and vitamin K were reduced to fluorescent derivatives in a zinc reactor column. Overall, vitamin K repeatability averaged 3.06% relative standard deviation (RSD) with a range of 0.99-7.16% RSD and reproducibility averaged 6.36% RSD with a range of 3.15-16.1% RSD. Repeatability (SMPR) were met for all 19 matrixes, and reproducibility SMPRs were met for 18 of the 19 product matrixes analyzed. Repeatability and reproducibility for total ( + ) vitamin K averaged 3.15% RSD with a range of 1.06-6.87% RSD and 6.11% RSD with a range of 2.94-16.7% RSD, respectively.
一项多实验室研究采用AOAC国际组织2015.09版第一方法“通过柱后还原和荧光检测的高效液相色谱法测定婴幼儿、儿童及成人营养产品中的叶绿醌及总维生素K”完成。来自六个国家的八个实验室参与了该多实验室研究。每个实验室对19种婴幼儿、儿童及成人营养产品进行了双份分析。所分析的产品基质包括牛奶、大豆、部分水解牛奶、部分水解大豆以及元素型婴幼儿配方奶粉；即食型牛奶基婴幼儿配方液体；儿童奶粉；成人低脂和高脂奶粉；以及高蛋白即饮型营养产品。蛋白质沉淀并用甲醇释放脂质后，用异辛烷从产品基质中提取维生素K。将制备好的样品注入硅胶高效液相色谱柱，其中叶绿醌和维生素K用异辛烷 - 异丙醇流动相进行分离。柱流出物与氯化锌、醋酸钠和醋酸的稀乙醇溶液混合，叶绿醌和维生素K在锌反应柱中还原为荧光衍生物。总体而言，叶绿醌的重复性平均相对标准偏差（RSD）为3.06%，范围为0.99 - 7.16% RSD，再现性平均RSD为6.36%，范围为3.15 - 16.1% RSD。对于所有19种基质均满足重复性标准物质相对标准偏差（SMPR），对于所分析的19种产品基质中的18种满足再现性SMPR。总（叶绿醌 + 维生素K）的重复性和再现性平均RSD分别为3.15%，范围为1.06 - 6.87% RSD和6.11%，范围为2.94 - 16.7% RSD。
