Marker dye mixture

Apply sample as a single spot about 5 cm from blotted end and small spots of the marker dye mixture Section 2.3.6. on each side of the sample. 

Marker dye mixture Mix equal volumes of 1% Xylene Cyanol F.F. (blue), 2% Orange G (yellow) and 1% Acid Fuchsin (pink) (all from George T. Gurr, Ltd., London.)... 

Marker dye mixture Dissolve 5 mg e-DNP-lysine (yellow) and 1 mg xylene cyanole FF (blue) in 1 ml of a 1 1 mixture of pH 4.72 electrophoresis buffer and deionized water. 

For the characterization of the chamber saturation a marker test dye mixture was proposed by Nyiredy et al. (40). The chromatograms of this dye mixture have to be developed with dichloromethane. The Ry range of the applied dyes depends on the chamber saturation. If the h/ /values of the marker dye mixture are the same in different chambers on a given stationary phase, the grade of the chamber saturation is identical. For comparison, the YiRj values obtained from different chambers can be depicted in a coordinate system. The hR/values of any given system are plotted along the y-axis and those from the system being compared ong the x-axis. If the chamber saturation is identical, a linear relationship has to be obtained, and tg a for the line is 1. 

The role of the vapor phase in TLC was reviewed in detail by Geiss (1988), but little attention is generally paid to it in normal practice. Separations obtained in TLC can be significantly affected by the vapor phase, which depends on the type, size, and saturation condition of the chamber. The interactions of the layer, mobile phase, and vapor phase, as well as other factors (Chapter 11), must be controlled to obtain reproducible TLC separations. A procedure was proposed by Nyiredy et al. (1992) for characterization of chamber saturation in FFPC based on the Rp range obtained on development of a marker test dye mixture with dichloromethane. It was concluded that as a general rule, a saturated chamber should be used for samples containing less than seven compounds to be quantified, whereas OPLC in unsaturated chambers with an optimized mobile phase is required for more than seven compounds or difficult separations. 

The sample solution band (test dye mixture), applied from the edge of the layer, formed a partly separated starting zone (frontal chromatography stage). After adsorption of the sample by the adsorbent layer, the eluent was introduced under the solvent distributor, and the marker (azobenzene) was spotted. The movements of the marker and the dye zones were recorded on a transparent foil (84). By connecting the points representing the upper and lower boundaries of the zones, a dynamic picture of the movement and separation of the zones could be obtained. 

Modem commercial explosives are generally mixtures of AN and fuel. These mixtures do not have the high detonation velocity exhibited by mihtary materials, but they do detonate satisfactorily. The key to their performance is an intimate mix of the oxidizer (AN) and fuel, such as in the formulation ANFO, where the fuel is allowed to soak into the AN. Often a dye is added as a safety marker to commercial ANFO, as otherwise there is no obvious visible difference between the explosive and neat AN. The latter is generally classed as an oxidizer and can be freely transported. 

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