Kreft's dichromaticity index
Kreft's dichromaticity index (DI) is a measure for quantification of dichromatism. It is defined as the difference in hue angle (Δhab) between the color of the sample at the dilution, where the chroma (color saturation) is maximal, and the color of four times more diluted (or thinner) and four times more concentrated (or thicker) sample. The two hue angle differences are called the dichromaticity index towards lighter (Kreft's DIL) and
dichromaticity index towards darker (Kreft's DID) respectively.
The color of pumpkin oil at increasing thickness or concentration presented in
Dichromaticity (DIL and DID) of selected substances, calculated from their VIS absorption spectra by the computer algorithm “Dichromaticity index calculator”:
Substance | DIL | DID | Maximal chroma | Angle at maximal chroma |
---|---|---|---|---|
1,1-diethyl-2,2-cyanine iodide | 4.3 | −1.1 | 107.1 | 44.6 |
acridine orange | - −10.1 | −17.9 | 118.4 | 88.3 |
acridine yellow | −2.1 | −1.7 | 123.1 | 98.6 |
auramine O | −3.4 | 0.4 | 130.1 | 94.7 |
beta carotene |
−5.7 | −7.0 | 131.8 | 91.5 |
bilirubin | −4.7 | −6.0 | 136.5 | 90.3 |
bromophenol blue at pH 3.0 | −12.4 | −31.1 | 107.6 | 86.6 |
bromophenol blue at pH 3.2 | −14.6 | −42.4 | 92.9 | 86.5 |
bromophenol blue at pH 3.4 | −48.9 | −14.1 | 74.5 | 37.8 |
bromophenol blue at pH 3.6 | −51.4 | −16.4 | 70.6 | 37.4 |
bromophenol blue at pH 3.8 | −49.8 | −18.3 | 65.5 | 34.3 |
bromophenol blue at pH 4.0 | −26.5 | −10.8 | 68.9 | 31.4 |
bromophenol blue in water | −13.0 | −34.7 | 104.7 | 86.4 |
C3 indocyanine | 8.2 | 17.3 | 89.3 | 348.0 |
chlorophyll a in ether | 29.2 | 60.7 | 50.4 | 201.4 |
chlorophyll b | 11.2 | 27.3 | 44.5 | 143.2 |
coumarin 6 | −2.0 | −0.3 | 131.2 | 96.5 |
coumarin 343 | −1.9 | 0.0 | 120.9 | 99.6 |
cryptocyanine | 37.9 | 1.9 | 84.3 | 301.3 |
crystal violet in glycerol | 9.7 | 3.3 | 141.3 | 318.3 |
crystal violet in water | 9.3 | 3.7 | 142.0 | 319.1 |
fluorescein dibase | −1.6 | −6.9 | 120.4 | 75.4 |
hemoglobin - oxy | −1.2 | −5.6 | 108.4 | 42.6 |
hemoglobin | −2.3 | −5.9 | 62.3 | 19.0 |
malachite green | 7.3 | 24.4 | 61.2 | 223.2 |
nile blue in methanol | 34.9 | 7.8 | 78.3 | 288.9 |
nile red | 18.5 | −9.5 | 103.2 | 45.9 |
proflavin at pH 7 |
−6.1 | −10.6 | 101.6 | 98.5 |
pumpkin seed oil | −9.0 | −44.1 | 59.8 | 102.2 |
resazurin | 33.2 | 40.6 | 36.2 | 331.3 |
rhodamine 6G | 21.9 | −0.8 | 110.5 | 54.4 |
vitamin B12 | 34.8 | −6.2 | 102.0 | 39.8 |
Maximal chroma: chroma at concentration (thickness) where the color of the substance has maximal chroma (saturation). Angle at maximal chroma: the hue, which is represented by the angle of the vector to the color with maximal chroma in the CIELAB colorspace diagram.
References
- PMID 19568292.