Dibutylphthalate absorption

From ASTM international NSA, nitrogen surfaee area, STSA, statistical thickness surface area, dibutylphthalate absorption. 

Caution The solution tubes must be kept tightly corked hereafter to prevent absorption of atmospheric moisture by the very dry dibutylphthalate, except during evacuation in the oven and while being weighed. 

Figure 9 Absorption spectrum (upper trace) and VES spectrum (lower trace) of the asymmetrical CO-stretching modes of W(CO)6 (centered at 1976 cm-1) and Rh(CO)2acac (centered at 2010 cm-1) in the solvent dibutylphthalate at room temperature. The vertical axis is in absorbance units for the upper trace. For the VES spectrum, the vertical axis is in arbitrary units. In the VES spectrum, the solvent background and solvent peaks are eliminated.

Phthalates are often used as plasticisers for polyvinyl, polyvinyl chloride or cellulose resins. They are esters of phthalic acid. The absorption maxima of diethylphthalate, dibutylphthalate and butylbenzylphthalate are around 275 nm (Fig. 64). 

Lengyel et al studied the separation of methylchlorosilanes on different supports and with different liquid. Celite and Sterch-amol were both satisfactory supports but Termalite (firebrick) had a strong selective-absorption effect, resulting in asymmetric elution curves. Of the stationary phases tested (liquid paraffin, silicone oil, 1-chloronaphthalene, dibutylphthalate and nitrobenzene), those with the highest dipole moments were the most effective. Celite impregnated with 23% of nitrobenzene gave complete separation of a six-component mixture. 

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