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The spectral transmissive properties of dyes: I. Seven Permitted Food Dyes in the visible, ultra-violet, and near infra-red
| Content Provider | Semantic Scholar |
|---|---|
| Author | Gibson, Kasson Stanford McNicholas, H. J. Tyndall, E. P. T. Frehafer, Mabel Katherine Mathewson, Walter E. |
| Copyright Year | 1921 |
| Abstract | This paper presents quantitative data on the spectral transmittancy of seven permitted food dyes in the ultra-violet, ^'^sible, and near infra-red, from wave length 240 to 1360 millimicrons. The dyes studied were Naphthol Yellow S, Orange I, Ponceau 3R, Amaranth, Erythrosine, Indigo Disulpho Acid, and Light Green S F Yellowish. All of these show the properties of indicators and were, with the exception of Erythrosine, all dissolved in distilled water containing a sufficient amount of an H-ion regulator to fix the acidity of the solvent within narrow limits. Erythrosine, however, was dissolved in pure distilled water. The data are given in the form of graphs and tables and a tentative nomenclature for the subject presented. The graph forms show the transmittancy and — log jq transmittancy as a function of wave length and frequency for different concentrations, thicknesses, and temperatures. Qsncentrations of i, 10, 100, and 1000 centigrams per liter, thicknesses of i, 2, 4, and 10 cm, and temperatiires of 25 and 40° C, were used. The tables give the specific transmissive indices of the solutions for homogeneous light of various wave lengths throughout the visible spectrum, as obtained from mercxuy and helium lamps, and also the values of index and frequency (and wave length) of the maxima and minima of the absorption bands throughout the whole range of wave lengths investigated. Four methods were used to obtain the data: (i) The visual method, using the Konig-Martens polarization spectrophotometer; (2) the photographic method, with the Hilger sector photometer and quartz spectrograph; (3) the photoelectric null method; and (4) the thermoelectric method. These methods are fully described and the apparatus illustrated by photographs and diagrams. The data as actually observed are plotted on the graph forms, and the wave length ranges of the different methods overlap sufficiently to afford a thorough study of the accuracy of meastuement attainable by these different methods. CONTENTS p^gg |
| Starting Page | 121 |
| Ending Page | 121 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| DOI | 10.6028/nbsscipaper.089 |
| Volume Number | 18 |
| Alternate Webpage(s) | https://nvlpubs.nist.gov/nistpubs/ScientificPapers/nbsscientificpaper440vol18p121_A2b.pdf |
| Alternate Webpage(s) | https://doi.org/10.6028/nbsscipaper.089 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
