Gerber H R
U.S. Food and Drug Administration, Division of Microanalytical Evaluations, Washington, DC 20204.
J AOAC Int. 1994 Sep-Oct;77(5):1146-9.
A collaborative study for determining mammalian feces in ground black pepper was conducted, using a modified version of the AOAC Official Method 986.28 for mammalian feces in grain products. With the proposed method, the presence of alkaline phosphatase, an enzyme found in mammalian feces, was determined by using phenolphthalein diphosphate as the enzyme substrate in a test agar medium containing 1% agar in a borate buffer, pH 9.5. Ground black pepper was stirred in water to extract interfering color. The mixture was filtered and the residue was scattered on plates of liquid test agar. The alkaline phosphatase cleaved phosphate radicals from phenolphthalein diphosphate, generating free phenolphthalein, which appeared as pink to red-purple around the fecal particles in the previously colorless medium. For the 10- and 20-particle spike level, collaborators recovered averages of 12.3 and 24.1 particles, respectively. The experimental background was zero. Collaborators reported that the method was clear and easy to perform.
开展了一项协作研究，以测定磨碎黑胡椒中的哺乳动物粪便，采用了美国官方分析化学师协会（AOAC）谷物产品中哺乳动物粪便的官方方法986.28的改良版。使用所提出的方法，通过在含有1%琼脂的硼酸盐缓冲液（pH 9.5）的测试琼脂培养基中，以酚酞二磷酸作为酶底物，来测定哺乳动物粪便中存在的碱性磷酸酶。将磨碎的黑胡椒在水中搅拌以提取干扰颜色。将混合物过滤，残渣散布在液体测试琼脂平板上。碱性磷酸酶从酚酞二磷酸中裂解出磷酸根，生成游离酚酞，在先前无色的培养基中，粪便颗粒周围会呈现出粉红色至红紫色。对于添加10个和20个颗粒的水平，协作人员分别平均回收了12.3个和24.1个颗粒。实验背景为零。协作人员报告称该方法清晰且易于操作。
