Residue on Evaporation

Non-volatile impurities in phosgene are determined by allowing a known quantity of the phosgene sample to evaporate and weighing the residue [458a,1394a]. Analysis of the residue obtained from the evaporation of the commercial samples of phosgene has revealed the 

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Good technical-grade ethyl chloride should not contain more than the following quantities of the indicated impurities water, 15 ppm acid (as HCl), 120 ppm residue on evaporation at 110°C, 50 ppm. Ethyl chloride does not require added stabilizers. 

Abdampfungs-gefass, n. evaporating vessel, -kessel, m. evaporating kettle or pan. -pfanne, /. evaporating pan. -rlickstand, m. residue on evaporation. 

The requirements of the US Armed Forces for phosgene are covered in specification Ml L-P-10455A (18 Apr 1951), which covers two grades Grade A - for use in munitions, max free chlorine 1.0%, and Grade B — for use in chemical manuf, max free chlorine 0.05%. Both grades are required to have a purity of 98.0% min, acidity (calcd as HC1) of 0.50% max, and residue on evaporation of 0.50%... 

Neutral oil consists of unreacted alkenes, alkanes, secondary alcohol byproducts, sulfonate esters, and sultones. Calculation of the concentration of neutral oil present in AOS, taken together with separate determinations for alkenes and alcohols (see below) and nonvolatile material (determined by residue on evaporation), can be used as a measure of the completeness of the sulfona-tion reaction. 

Lindquist and Dias [26] have described a Zymark Py Technology System which automates and integrates four methods total dissolved sohds (TDS) dried at 180°C, TDS residue on evaporation (TOS-ROE) dried at 103—10S°C, total suspended solids (TSS) dried at 103-10S°C, and total sohds (TS) dried at 103-10S°C. Approved Environmental Protection Agency (EPA) or equivalent methods are used. A TurboVap Evaporator has been incorporated into the design to speed up the sample evaporation. 

Residue on Evaporation. — 25 cc. of acetone on evaporation should leave no weighable residue. 

Non-volatile Matter. —10 cc. of acetic acid should leave no weighable residue on evaporation. 

Under the influence of light, carbon disulphide becomes yellowish, and then leaves a slight residue on evaporation. 

Material Soluble in Alcohol. — Heat a mixture of 1 gm. of animal charcoal and 20 cc. of alcohol to boiling, and filter. The filtrate should leave no weighable residue on evaporation. 

Determination of Residue. — On evaporating 10 gm. of collodion on the water-bath, it should leave a residue, which, when dried at 100° C., should weigh 0.38 to 0.40 gm. 

Residue on Evaporation (Sulphuric and Phosphoric Acids, etc.). —10 cc. of the hydrogen peroxide, when heated on the water-bath, should completely volatilize and leave no weigh-able residue. 

These mixtures are not completely soluble in 90% alcohol, except in presence of castor oil, which is, however, only slightly soluble in 70% alcohol. When, therefore, they are evaporated in a dish on a water-bath, they leave an abundant residue which has a high saponification number (180-200) and emits an irritating odour of acrolein when heated in a test-tube with potassium bisulphate. Certain ethereal oils (bergamot, lemon, aniseed and badiana oils) themselves leave a residue on evaporation, but such residue has not the characters of the fatty oils. The saponification number of the oil itself may raise suspicion as to the presence of fatty oil. 

This is obtained from the peel of the fruit of Citrus aurantium (var. dulcis) and is a golden-yellow liquid with an odour of oranges and a sweetish, aromatic taste. It contains limonene (about 90%), linalool, terpineol, nonyl alcohol, decyl aldehyde and esterified caprylic acid. If adulterated with bitter orange cal (q.v.), the latter is detectable by determinations of the sp. gr. at 15°, rotatory power and residue on evaporation (see Oil of Lemon) and by fractional distillation. 

On fractional distillation by the Soldaini and Bertd method (see Oil Of Lemon), the rotation should be raised by at least x° 30 and the residue On evaporation should be 2-4%. 

Residue on Evaporation.—5 grams of the oil are evaporated in a tared dish on a water-bath until the odour disappears, the residue being then weighed and calculated for 100 grams of the oil. 

The residue on evaporation Of the genuine oil is 5-6% and its ester number 138-180, corresponding with 47-6-63% of linalyl acetate the 5-6 grams of residue are thus equivalent to about 2VJ-3-8 grams of linalyl acetate. Oil of lemon, terpenes, rectified bergamot oil or mineral oils diminish the residue... 

Residue on evaporation. Genuine oil obtained by the sponge process by hand leaves 2-3-5% °f residue, while that obtained mechanically may leave 5%. When the latter is distilled by the Soldaini and Bert6 method, the rotation of the distillate is usually about 2° above that of the original oil. 

The residue on evaporation is scarcely appreciable for the fresh, genuine oil, while crude or old, resinified oil may leave 2% of residue. 

Note 1. If the residue on evaporation does not redissolve after warming it 10 minutes with 60 cc. of water, it contains arsenious oxide either from incomplete oxidation by nitric acid, or from a decomposition of arsenic pentoxide by overheating. Test 1 cc. of the suspension containing the undissolved substance by adding 10 cc. of water, then solid sodium bicarbonate until no more effervescence occurs, and then a considerable quantity in excess. Add to this a solution of iodine, drop by drop. The amount of the latter which is decolorized (if any) corresponds to the amount of arsenious acid (As203), which was in the sample. 

Refractive Index Between 1.465 and 1.468 at 20°. Residue on Evaporation Not more than 6.0%. 

Residue on Evaporation Determine as directed under Residue on Evaporation, Appendix VI, heating a sample for 5 h. Solubility in Alcohol Determine as directed under Solubility in Alcohol, Appendix VI. One milliliter of sample dissolves... 

Phosphate Evaporate 400 mg of sample to dryness on a steam bath. Dissolve the residue in 25 mL of approximately 0.5 N sulfuric acid, add 1 mL of ammonium molybdate solution [500 mg of (NH4)5Mo7024 4H20 in each 10 mL of water] and 1 mL of p-methylaminophenol sulfate TS, and allow it to stand for 2 h. Any blue color does not exceed that produced by 2.0 mL of Phosphate Standard Solution (20 pig PO4) (see Solutions and Indictors) in an equal volume of solution containing the quantities of the reagents used in the test. Residue on Evaporation Evaporate 25 g of sample to dryness in a tared porcelain or silica dish on a steam bath, and... 

Residue on Evaporation Mexican Type Between 10.0% and 14.5% Tahitian Type Between 5.0% and 12.0%. Specific Gravity Mexican Type Between 0.872 and 0.881 Tahitian Type Between 0.858 and 0.876. 

Residue on Evaporation Determine as directed under Residue on Evaporation, Appendix VI, using a 3-g sample and... 

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