A visiting professor at NIST once pointed out that our measurement professionals are given a difficult task by some of our customers. In a (macroscopically) continuum universe, we are asked to perform measurements with tools and techniques of finite precision and in the end to produce digital answers, preferably binary: yes or no, safe or unsafe, above or below the regulatory limit. A common tr...

We have developed a qualitative method to assay for the presence of 2-deoxystreptamine in hydrolysates of crude aminoglycoside preparations using a 2-deoxystreptamine-requiring idiotrophic mutant. The assay involves (i) incubation of a 2-deoxystreptamine-requiring mutant with 1 mg of a hydrolyzed preparation from a crude unknown antibiotic mixture per ml, and (ii) examination of the resultant i...

Introduction Background and literature sources Specialized journals Internet addresses Previous reviews Fundamentals of the technique Principles of NIR spectroscopy NIR diffuse reflectance spectroscopy Operational procedures in the NIR Mathematical processing of signals Qualitative analysis Identification and qualification of raw materials and pharmaceutical preparations Determination of homoge...

All heptoses produce with orcinol in dilute HCl two characteristic colored compounds which differ greatly in their absorption spectra. Three different modifications of this reaction were found useful. Procedure i--To 2 cc. of a solution containing 20 to 100 y per cc. of ketoheptose or 5 times as much of an aldoheptose is added 0.4 cc. of concentrated HCl, sp. gr. 1.19, in a test-tube with a gro...