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Dyes, analysis

Considerable evidence can be obtained from the analysis of colourants since dyes are encountered in a wide range of casework samples including [Pg.230]

Many of the HPLC dye applications require the analysis of trace levels of dyes. For example with the examination of fibre dyes, the casework sample is typically a single strand of fibre which is only 2 5 mm in length and the dye content is approximately 10 ng. Fortunately, because of the relatively high absorptivity of dyes, these detection levels can be achieved by using a visible wavelength detector and a column with an internal diameter of 3.2 mm. By employing a column of this diameter as opposed to the standard 4.6 mm, less dilution of the sample occurs and can effectively increase sensitivity by a factor of between two and three. Microbore columns, i.e. columns with diameters of smaller than 2 mm are not favoured for routine analyses beeause of diffieulties in maintaining their efficiency and reproducibility. [Pg.231]

There is a trend in the HPLC analysis of dyes to move towards the use of multi-wavelength detectors. The ability to produce simultaneous multiwavelength plots is a very useful feature of this type of detector because [Pg.231]


Successful combination of a chromatographic procedure for separating and isolating additive components with an on-line method for obtaining the IR spectrum enables detailed compositional and structural information to be obtained in a relatively short time frame, as shown in the case of additives in PP [501], and of a plasticiser (DEHP) and an aromatic phenyl phosphate flame retardant in a PVC fabric [502], RPLC-TSP-FTIR with diffuse reflectance detection has been used for dye analysis [512], The HPLC-separated components were deposited as a series of concentrated spots on a moving tape. HPLC-TSP-FTIR has analysed polystyrene samples [513,514], The LC Transform has also been employed for the identification of a stain in carpet yarn [515] and a contaminant in a multiwire cable [516], HPLC-FTIR can be used to maintain consistency of raw materials or to characterise a performance difference. [Pg.496]

LC-TSP-MS without tandem mass capabilities has only met with limited success for additive analysis in most laboratories. Thermospray ionisation was especially applied between 1987 and 1992 in combination with LC-MS for a wide variety of compound classes, e.g. dyes (Fig. 7.31). Thermospray, particle-beam and electrospray LC-MS were used for the analysis of 14 commercial azo and diazo dyes [594]. No significant problems were met in the LC-TSP-MS analysis of neutral and basic azo dyes [594,595], at variance with that of thermolabile sulfonated azo dyes [596,597], LC-TSP-MS has been used to elucidate the structure of Basic Red 14 [598]. The applications of LC-TSP-MS and LC-TSP-MS in dye analysis have been reviewed [599]. [Pg.513]

Serbedzija, G. N., Bronner-Fraser, M., and Fraser, S. E. (1992). Vital dye analysis of cranial neural crest cell migration in the mouse embryo. Development 116 297-307. [Pg.176]

Verhecken, A. (2005), A concise history of dye analysis, Dyes in History and Archaeology 20, 1-22. [Pg.622]

J. Wouters andN. Rosario Chirinos, Dye analysis ofpre Columbian Peruvian textiles with high performance liquid chromatography and diode array detection, J. Am. Inst. Conserv., 31, 237 255 (1992). [Pg.388]

The legal or illegal application of synthetic dyes in foods and food products increases consumer acceptance, and consequently, the profit of the producer. As a considerable quantity of foods and food products contain dyes, their determination is of considerable importance. Electrophoretic techniques have been frequently employed for dye analysis. Thus, micellar electrokinetic capillary chromatography has also been employed for the determination of synthetic colours in soft drinks and confectioneries [183],... [Pg.516]

This method has been used to analyze both symmetrical (C.I. Direct Red 28 and C.I. Direct Blue 6) and unsymmetrical (C.I. Direct Black 38 and C.I. Direct Brown 95) benzidine-based dyes. Based on this work, the application of the method to other benzidine-based dyes should be straightforward. When field samples are submitted for benzidine-based dye analysis, bulk samples of the dyes present in the sample also should be submitted. With these bulk samples, the analyst should be able to determine if this method is applicable to the various dyes submitted and if any interferences are present. The method presently has not been tested on field samples. An existing sampling method (J 3) for azo dyes and diazonium salts should be directly applicable to this method with a change from a cellulose ester to a Teflon filter. This change is necessary to insure quantitative recovery of the sample from the filter. [Pg.32]

Another robe belonging to the coronation costumes of the emperors of the Holy Roman Empire of the German Nation is the Tunicella illustrated in Figure 11, which was made in the first half of the 12th century in the royal court workshop in Sicily. I received 23,9 mg of the dark blue dress material and 15,3 mg of the red border for a dye analysis. IR spectra comparison of the dye shaken out of the vat with ethyl acetate showed unambiguously that indigo had been used to dye the dark blue dress material. [Pg.215]

Daniels, V., "Progess in the dye analysis in the British Museum", in Dyes on historical and archaeological Textiles 3rd Meeting, York Archaeological Trust, Sept.1984, 8. [Pg.217]

Dye Analysis of a Group of Late Intermediate Period Textiles from lea, Peru... [Pg.287]

TAye analysis, especially in conjunction with other research, can provide much information for those entrusted with historic textiles. Information regarding the effects of pesticides, conservation procedures, storage environments, and exhibition conditions on fibers and dyes will allow curators and conservators to make decisions in the best interest of the preservation of the textiles. In the past, dye analysis of historic textiles has not always been successful, attributable to a great extent to the small sample sizes afforded. Refinements in the field of thin layer chromatography, especially in adsorbants, has made dye analysis much more... [Pg.287]

Inasmuch as there is a lack of the more exact bases analogous to those on which the science of analytical chemistry is built, methods must sometimes be used which are not encountered in scientific research. Basically, however, the methods of modem dye analysis involve the same general principles as the classical analytical procedures. First of all, one must rely upon the available literature to gain a clear opinion as to how to proceed. Today, this literature is not contained, or is contained in only exceptional cases, in the scientific publications which are eventually collected in reference books like those of Beilstein and Gmelin-Kraut. There are, however, other sources which are useful in many cases. These sources are published patents, the trade journals of dye chemistry, and technical communications, all of which may give hints about a product in question. [Pg.215]

Since it is not within the scope of this book to go into great detail, we shall consider only the general principles of azo dye analysis. [Pg.216]

Chrysophenine G, 149, 283 Clayton yellow, 336 Cleaning of reaction vessels, 10 Cleve acids, see 1,6- and 1,7-Naph-thylaminesulfonic adds Coal tar, 1 Columbia black, 187 Commerdal dyes, analysis, 399 Compressed air, 373 Condensers, 22, 26 Congo red, 293 test paper, 395... [Pg.249]

The once widely used works, therefore, could no longer be used as the foundation for modem dye analysis, and new methods, independent of the older works, had to be worked out. [Pg.467]

It would lead too far afield to try to present all the known facts in this book. On the other hand, it is of interest that the beginner should become acquainted, at least in broad outline, with the principles of modem dye analysis. To this end, references to publications in this... [Pg.467]

Sample preparation presented the most likely source of potentially misleading chromatographic results. We are continuing to work on improved extraction techniques and are also continuing to explore the applicability of the systems studied for early synthetic dye analysis. [Pg.184]

Dyes have been traditionally analysed by thin-layer chromatography (TLC) and then more recently by high-performance liquid chromatography (HPLC). GC is not normally suitable for dyes since dyes are generally non-volatile ionic or strongly polar compounds. The most popular form of dye analysis by HPLC... [Pg.302]

The AATCC system is a very detailed dye class identification system. The brief description of some basic tests in this chapter is only for the purpose of introduction. Readers are recommended to obtain thebook Analytical Methods for a Textile Laboratory by the AATCC in order to comprehend the complexity of the dye analysis. Of course the other books and journal articles listed in the references are also excellent information sources. Whenever possible, reading these materials would definitely help develop a better understanding of colour chemistry, which will ultimately ensure that the dye analysis is performed more effectively and efficiently. [Pg.312]


See other pages where Dyes, analysis is mentioned: [Pg.515]    [Pg.515]    [Pg.51]    [Pg.31]    [Pg.507]    [Pg.676]    [Pg.50]    [Pg.215]    [Pg.554]    [Pg.287]    [Pg.291]    [Pg.7]    [Pg.176]    [Pg.230]    [Pg.309]   
See also in sourсe #XX -- [ Pg.230 , Pg.231 ]




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