Fluorescent blue

After the dipped or sprayed chromatogram has been dried in a stream of cold air long-wave UV light (2 = 365 nm) reveals fluorescent yellow zones (flavonoids). Sterigmatocystine, which can be detected without derivatization on account of its red intrinsic fluorescence (detection limit 0.5 pg), also fluoresces pale yellow after being heated to 80°C [9] or 100°C [13] for 10 min on the other hand, citrinine, zearalenone and vomitoxin fluoresce blue. [Pg.148]

Fluorescent blue-green chromatogram zones appear on a dark background in long-wavelength UV light (A = 365 nm). [Pg.295]

The proportion of hydrochloric acid in the mobile phase was not to exceed 20%, so that complex formation did not occur and zone structure was not adversely affected. An excess of accompanying alkaline earth metal ions did not interfere with the separation but alkali metal cations did. The hthium cation fluoresced blue and lay at the same height as the magnesium cation, ammonium ions interfered with the calcium zone. [Pg.312]

Detection and result The chromatogram was dried in a stream of cold air, immersed in the reagent solution for 5 s, dried in the air and then heated to 120°C for 7 min. It could be inspected after allowing to cool for 30 min. Carbamazepine hRf 30— 35) fluoresced blue in long-wavelength UV light (2 = 365 nm). [Pg.366]

Chelerythrine crystallises from alcohol in colourless, prismatic leaflets, m.p. 207°, containing one molecule of alcohol. The alkaloid absorbs carbon dioxide from the air, becoming yellow. The solutions fluoresce blue when the alkaloid is contaminated with its oxidation product, which is formed by mere exposure of solutions to air. The salts, which are quaternary, are intensely yellow. The hydrochloride, B. HCl. HjO, forms citron-yellow needles, and the sulphate, B. H2SO4.2HjO, golden-yellow needles, sparingly soluble in water the platinichloride, B2. HaPtCl. ... [Pg.277]

Leonard and Elderfield have also carried out degradation experiments with alstonine and its tetrahydride. On fusion with potassium hydroxide at 300-350° in nitrogen, alstonine furnishes barman (p. 490) and indefinite basic and acidic fractions. Tetrahydroalstonine on like treatment produces barman, worharman, and three unidentified bases, each of which fluoresces blue in alcoholic hydrochloric acid Base A, C4,H4gN2, m.p. 171-5 to 172-5°, forms a picrate, m.p. > 267° is probably a substituted -carboline. Base B, or 18 3, gives apicrate, m.p. 261° (dec.). Base C,... [Pg.717]

Lunamarine, CjgHjjO N, probably identical with the limacridine of Dieterle and Beyl. M.p. 245-6°, [a]D 0°. Solutions in alcohol fluoresce blue in ultra-violet light. ... [Pg.752]

Prechromatographic dansylation has the advantage that chromatography separates excess reagent and also the fluorescent by-products (e g dansyl hydroxide) from the reaction products of the substances to be determined In the case of postchromatographic dansylation the whole of the plate background fluoresces blue, so that in situ analysis is made more difficult... [Pg.44]

The observed fluorescence blue shift following BLG adsorption was, however, small compared with the one observed for bovine serum albumin [28]. Univariate analysis... [Pg.268]

The sol-gel co-immobilization of a non-fluorescent blue indicator bromothymol blue (BTB) with an europium (Ill)-complex intense antenna mediated lanthanide dye represents a new scheme for the fluorescence analysis38. Luminescence spectra of europium (Ill)-complex shown in Figure 12 were found to be independent of pH changes in the range 1-10. Therefore, BTB, a non-fluorescent pH indicator with alkaline absorption maximum close to main europium emission band was added to the sol-gel mixture to shield reversibly the emission of the europium (Ill)-complex at different pH s without quenching of the antenna function. [Pg.88]

Delayed action cytotoxins that inhibit the synthesis of nucleic acids. They are obtained from various molds/fungi (Aspergillus flavus, Aspergillus parasiticus). They are colorless to pale-yellow crystalline materials melting above 450°F. The "B" toxins fluoresce blue in the presence of UV light while the "G" toxins fluoresce green. They are only slightly soluble in water, but are soluble in methanol, acetone, and chloroform. Aqueous solutions are "probably stable" and "probably tolerant" to chlorine at purification concentrations. [Pg.479]

The most widely used fluorescent blue host materials are anthracene and distyryl-based compounds as shown in Scheme 3.38. These materials have good phase-compatibility with... [Pg.337]

These materials have large band gaps and are thermally stable with high Tg. Details describing the use of these materials will be presented in the section on fluorescent blue dopants. [Pg.338]

The most efficient fluorescent blue emitters yet reported belong to the distyrylarylene (DSA) series (Scheme 3.56) and it is likely that the first generation of commercial blue OLEDs will use these materials as emitters or hosts. [Pg.350]

Fluorescent blue colours are less common and are usually in the bright turquoise shade area, with anthraquinones such as Cl Disperse Blue 60 or the newer methines such as Cl Disperse Blue 354 or indoanilines being the products of choice. Typical products from the ranges of DyStar and BASF (textile colours business is now part of DyStar) are given in Table 3.7. [Pg.183]

The host-guest p-cyclodextrin-C522 complex formation was determined based on fluorescence blue shift as a function of the increasing p-cyclodextrin concentration from 10 6 to 10 2 M. Similar result was observed for coumarin C6 [4] and this blue shift was considered along with anisotropy results as a proof of the host-guest formation. Time-resolved fluorescence spectroscopy was utilized to differentiate between fluorescence dynamics of... [Pg.238]

Green-fluorescing Zn2Si04 Mn2+ and magnesium tungstate that fluoresces blue under short-wavelength UV are mixed with the sorbents (silica gel, aluminum oxide) of TLC plates in proportions of ca. 3 wt% to improve the contrast in the detection of UV-absorbing compounds. [Pg.261]

Crystallises in pale yellow leaflets, which contain 2 mols. of water slightly soluble in water its neutral solution fluoresces blue, its acid solution violet, and its alkaline solution green on heating it decolorises at 230°. (B., 33, 675 D.R.P., 117005.)... [Pg.160]

Quinine Formic acid vapors Fluorescent blue spots 3... [Pg.208]

Another method of measuring the relative quantum yield of the radical decomposition process (eq. 22) was also devised recently (144). This involves HNO chemiluminescence photoexcitation spectroscopy. When an H atom recombines with an NO molecule, an electronically excited HN0 ( A A" ) is formed. Fluorescence emission from HNO occurs at 762 nm. The HNO chemiluminescence in a low-pressure 1 10 mixture of H2CO and NO is proportional to the H-atom quantum yield from the photolysis of H2CO. The photoexcited HNO (red) chemiluminescence excitation spectrum of a H2CO/NO mixture obtained with a tunable laser at high resolution is shown in Fig. 2 together with an absorption spectrum and a H2CO fluorescence (blue) excitation spectrum (237). The relevant reaction scheme is as follows ... [Pg.21]

Under ultraviolet light freshly cut or polished burmite fluoresces strongly with a striking, mid-blue colour (Fig. 1.16). Less fresh pieces may fluoresce with a beige colour. Burmite also fluoresces blue in sunlight, and, like Mexican amber, this fluorescence appears to come from the body of the amber rather than from the surface. [Pg.15]

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