Distillation Range Testing

Phenol quahty tests and analyses can be divided into two categories wet lab and Hquid and gas chromatography. In the wet lab, phenol is tested for pH, sohdification point, solubiUty in water, bromine index, color, and distillation ranges. Phenol concentration, impurities, and CHP contents are analy2ed using highly automated Hquid and gas chromatography. 

Peroxides. These are formed by aerial oxidation or by autoxidation of a wide range of organic compounds, including diethyl ether, allyl ethyl ether, allyl phenyl ether, dibenzyl ether, benzyl butyl ether, n-butyl ether, iso-butyl ether, r-butyl ether, dioxane, tetrahydrofuran, olefins, and aromatic and saturated aliphatic hydrocarbons. They accumulate during distillation and can detonate violently on evaporation or distillation when their concentration becomes high. If peroxides are likely to be present materials should be tested for peroxides before distillation (for tests see entry under "Ethers", in Chapter 2). Also, distillation should be discontinued when at least one quarter of the residue is left in the distilling flask. 

Distillation range the difference between the temperatnre at the initial boiling point and at the endpoint, as obtained by the distillation test. 

Technical grade chlorobenzene intended for use by US Dept of Defense as a solvent or as a raw material in the manuf of various chemicals, shall meet the following requirements specific gravity 1.101 1.112 at 20/4° acidity, as HC1 0.015%) moisture 0.1% and distillation range 131 32° at 760 mm Hg. Tests are described in... 

Distillation Range Not more than 10% distills below 165°. Refractive Index Between 1.475 and 1.480 at 20°. Solubility in Alcohol Passes test. 

Properties Volatile, colorless liquid. Fp -90.595C, bp 98.428C, refr index 1.38764 (20C), d 0.68368 (20C), flash p 25F (-3.89C) (CC). Soluble in alcohol, ether, chloroform insoluble in water distillation range 93.3-98.9C vap press 2.0 psi (a)(37.7C) (max). Color Saybolt +30 (min), maximum sulfur content 0.01 wt %, corrosive passes ASTM D 130-30 test, autoign temp 433F (222C). 

The preliminary assay provides general data on the oil and is based on simple tests such as distillation range, water content, specific gravity, and sulfur content that enable desirable or undesirable features to be noted. This form of assay requires only a small quantity of sample and is therefore particularly useful for the characterization of oil field samples produced from cores, drill stem tests, or seepages. 

Distillation range (°Q Acidity (ppm) max. (expressed as acetic add) Water (ppm) max. Non-volatile residue (ppm) max Permanganate test (minutes) min. Color (Pt Co) max. ... 

Fig. 10. Allelopathic effect of soil on mungbeans and lettuce seedlings after 72 h. Legend Soil (5 g) was placed on filter paper, distilled water and seeds were added, and the culture was set to incubate. Bars having different letters are significantly different, P = 0.05, ANOVA, with Duncan s Multiple-Range Test.

Several methods of determination can be used, but two, distillation and gas chromatography are the most popular. Industrial aromatic hydrocarbons are determined by distillation. The temperature is recorded for the initial boiling point, for the sample which has been distilled at 5%, 10%, then at 10% increments up to 90%, then finally at 95%. The temperature should be recorded with precision of 0.1 C. A general test mediod to determine the distillation range of volatile liquids" outlines a similar method of measurement In addition to the measurements at the intervals given above, the temperature of the dry point (distillation temperature of residual quantities) is also recorded. Results must be reported as specified in the method. 

ASTM D 1078-97. Standard test method for distillation range of volatile organic liquids. 

Analytically, distillation is used for two principal purposes, firstly as a criterion of purity and secondly as a means of preparing a sample for analysis. Many specification tests include reference to a distillation range within the limits of which a stated percentage of the material of interest distils. Alternatively, distillation may be used to separate volatiles from a sample prior to a suitable analytical technique being employed on the distillate or on the residue. Standard tests are documented that involve distillation as a sample pretreatment method prior to titrimetry, potentiometry, and spectrophotometry. 

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