Red Dyestuff Research Articles

Identification of anthraquinone coloring matters in natural red dyes by electrospray mass spectrometry coupled to capillary electrophoresis

Capillary electrophoresis with UV/visible diode-array detection (DAD) and electrospray mass spectrometric (ESI-MS) detection were used for the identification of anthraquinone color components of cochineal, lac-dye and madder, natural red dyestuffs often used by ancient painters. For the purpose of such analysis, ESI-MS was found to be a much more appropriate detection technique than DAD one owing to its higher sensitivity (detection limits in the range 0.1-0.5 micro g ml(-1)) and selectivity. The method developed made it possible to identify unequivocally carminic acid and laccaic acids A, B and E as coloring matters in the examined preparations of cochineal and lac-dye, respectively. In madder, European Rubia tinctorum, alizarin and purpurin were found. The method allows the rapid, direct and straightforward identification and quantification of components of natural products used in art and could be very helpful in restoration and conservation procedures.

Identification of anthraquinone coloring matters in natural red dyestuffs by high performance liquid chromatography with ultraviolet and electrospray mass spectrometric detection

AbstractReversed phase liquid chromatography with diode array detection (DAD) and electrospray mass spectrometric (ESI MSD) methods were developed for the identification of anthraquinone color components of cochineal, lac dye, and madder – red natural dyestuffs. Electrospray mass spectrometry was found to be more suitable than diode array detection for such analysis because of its higher sensitivity (detection limits in the range 30–90 ng mL–1) and selectivity. The developed method permitted unequivocal identification of carminic acid and laccaic acid A as coloring matters in examined preparations of cochineal and lac dye, respectively. In madder more chemical color species were found: alizarin, purpurin, lucidin, ruberythric acid, and also aluminum and calcium alizarin lake. Among the methods recommended so far, the present one allows fast, direct, and unequivocal identification of components of very complicated natural products used in art.

Dyeability of cellulose fibers using dyestuff from African rosewood (Pterocarpus erinaceous)

Methanol extracted from the “heart wood” of the plant Pterocarpus erinaceous (African rosewood) gave a brick red dyestuff. Chromatographic separation of the dye produced a single homogenous component with an Rf value of 0.78, a yield of about 17.3% and a melting point of 86°C. IR spectrum of the purified dye showed the presence of an aromatic CC double bond band at 1620–1470 cm−1 and NH2 absorption characteristic of an aromatic amine NH stretch at 3590–3400 cm−1, while para-disubstitution on aromatic nucleus was observed at 850–840 cm−1. A wavelength of maximum absorbance, λmax, of 500 nm was recorded on a UV/visible scan for the solvent soluble dye. The dye, which was substantive to cotton, was applied quantitatively to it and reed fibers by exhaust dyeing technique from locally distilled alcohol. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 746–751, 2000

Dictionary of word origins

What is the link between map and apron, acrobat and oxygen, zeal and jealousy, flour and pollen, secret and crime? Did you know that crimson originally comes from the name of tiny scale insects, the kermes, from whose dried bodies a red dyestuff is made? That Yankee began as a nickname for Dutchmen? That omelette evolved from amulette, a thin sheet of metal, and is a not-too- distant cousin of the word laminate? That jeans find their antecedent in jean fustian, meaning a cotton fabric from Genoa ? The Dictionary of Word Origins uncovers the hidden and often surprising connection between words. Written in a clear and informative style, the more than 8,000 articles reveal the origins of and links between some of the most common English-language words. They also contain an extensive selection of words whose life histories are intrinsically fascinating or instructive. This dictionary shows how modern English has developed from its Indo-European roots and how the various influences on the languagefrom migration and invasion to exploration, trade, technology, and scholarshiphave intermingled. It is an invaluable addition to any English or linguistics library.

Microspectrofluorimetry of fluorescent dyes and brighteners on single textile fibres: Part 1 — Fluorescence emission spectra

Objective discrimination of fluorescent brighteners on single textile fibres is difficult to achieve by current methods; the technique of microspectrofluorimetry provides a solution to this problem. The modifications necessary to convert a microspectrophotometer into a microspectrofluorimeter and the limitations imposed by such conversion are described. The use of the instrument for the discrimination of fluorescent brighteners and fluorescent red dyestuffs on single fibres is also examined.

New non-linear polycyclic azaphenothiazine dyestuffs

The synthesis of some new angular and Y-shaped azaphenothiazine ring systems from simple heterocyclic compounds is described. 3-Nitration of pyridin-4[1H]-one ( 7) followed by reduction and thiation with P 2S 5 gave 3-aminopyridine-4 [1H]-thione ( 10) in good yields. Reaction of product 10 with 2,3-dichloro-1,4-naphthoquinone ( 12) gave a red dyestuff, 6-chloro-7-thia-10,12-diazabenz [a]anthracen-5-one ( 13) having a new angular azaphenothiazine ring system. Two facile methods were also proposed for the synthesis of 15,16-dithia-1,5,10-triazahenzo[h]pentaphene ( 26) from 3-aminopyridine-2[1H]-thione (25, R= H) and 2-aminothiophenol. The purple pigment 26, R= H is the parent compound of this Y-shaped azaphenothiazine. Reduction of these dyestuffs ( 13 and 26) and their derivatives led to loss of colour which reappeared on exposure to atmospheric oxygen. This property makes them applicable as vat dyes. Additionally they were found to be good colorants for soap, candle, polish, paint and plastic materials.

Farbstoffanalytische Untersuchungen zum polarisationsmikroskopischen Nachweis von Kollagen mit Solaminrot 4B (Teil II)

We use the disazo dyestuff Solaminrot 4B for the visualization of collagen fibres in the morphological substratum investigated. The dye selectively enhance the birefringency of the fibres. Therefore, the parts of this paper are dealing with the dye properties of 2 charges of Solaminrot 4B produced by Chemie AG Bitterfeld--Wolfen. The 1st charge contain supplementary substances; the 2nd charge is without ones. We used various physicochemical methods, e.g. chromatography, spectroscopy, and electrophoresis. Moreover, we analyzed the solubility of dye in inorganic and organic solventia, the phase dispersion in benzen and octanol, the influence of the dye probes on the pH values of the dye solutions, and so on. The results indicate that the physicochemical properties of both charges investigated by us are partially different. This is important for the application of Sirius Red dyestuffs to the histological staining procedures.

High performance liquid chromatography of anthraquinones: analysis of plant and insect extracts and dyed textiles

Separation and quantitative determination of anthraquinones is achieved by high performance liquid chromatography in mixtures of methanol, water and formic acid on a reversed-phase stationary phase. The products are identified by retention time and, more accurately, by standard additions and UV-visible spectroscopy. This methodology has been applied to extracts of plant roots and insects, commonly used in earlier times as the source of red dyestuffs for dyeing textiles. Quantitative evaluation of the anthraquinone derivatives present in ancient red dyes was earned out after acid hydrolysis of 0·2 to 2·0mg of textile fibre. Due to the great sensitivity of the method, important minor constituents, such as kermesic acid in cochineal, can be detected.

Novel digital methods for the qualitative characterisation of some acid dyes applied to wool and nylon

The identification of dyes on textile fibres by assessment of reflectance curves is difficult owing to the dependence of spectral reflectance on concentration and spectral interference due to the base colour of the substrate itself. A method of analysis is proposed in which concentration effects are reduced or eliminated by the use of log (K/S) spectra, a function that is analogous to log(absorbance) as classically used in solution studies.Differentiation of the log(K/S) spectrum suppresses interferences arising from the broad background absorption of the fibre, so that the resulting profile generated is a property of the dyestuff alone. The wavelengths at which peaks, troughs and zero crossings are observed may be used to characterise the dyestuff itself. The method possesses greater sensitivity than conventional spectral reflectance or K/S curve analysis. Although the proposed method has been found to have limited utility in distinguishing between closely related acid red dyestuffs that possess almost identical light-absorbing properties, it does afford a rapid and convenient method for characterising acid dyestuffs on wool and nylon fibres.

Relationships between synthetic dyes and drug entities.

Drugs and dyes developed individual characters in the nineteenth century only. Drugs were at first “special foods” used during times of unpleasant symptoms or during illness. Consequently most drugs were vegetable or animal, since mineral technology was undeveloped. The earliest knowledge of dyestuffs was also acquired from the vegetable and animal kingdoms, especially the former. “Red dyestuffs were prepared from kermes, arachil, madder and henna; yellows from safflower, saffron, turmeric and pomegranate; blue from indigo and woad; purple from certain Mediterranean snails. Mordants containing iron, aluminium and copper were in use”. These latter were components of readily available earths.

Red Cochineal Dye (Carminic Acid): Its Role in Nature

Carminic acid, the well-known red dyestuff from cochineal insects (Dactylopius spp.), is a potent feeding deterrent to ants. This deterrency may be indicative of the natural function of the compound, which may have evolved in cochineals as a chemical weapon against predation. The behavior of an unusual predator is described-the carnivorous caterpillar of a pyralid moth (Laetilia coccidivora)-which is undeterred by carminic acid and feeds on cochineals. The animal has the remarkable habit of utilizing the ingested carminic acid for defensive purposes of its own.

Studies on Kusakizome (II) The Red Dyestuffs in Ancient Times

Studies on Kusakizome (II) The Red Dyestuffs in Ancient Times

Kinetics of the Decolorization of Congo Red under Ultrasonic Radiation

The fading of the color of the congo red dyestuff at concentrations 0.016. 0.01, and 0.005 g per liter under the influence of ultrasonic radiation from a Mullard generator with barium titanate crystal having a frequency of 1 Mc/sec and power output 225 w has been studied and the reaction is found to be unimolecular, the average velocity constants being respectively, 0.129, 0.209, and 0.193. The fading of congo red is not due to the production of hydrogen peroxide, and it is neither an oxidation nor a reduction process in the ordinary sense. The high cavitation energy appears to be responsible for the breaking down of the molecule of congo red resulting in the color fading.