Acetonitrile

“ SAMPLE PREPARATION:
6. 7.
8.
9.
NOTE: UV light may degrade PAHs; therefore, recommend using yellow, UV-absorbing shields for fluorescent lights or use incandescent lighting. Refrigerate samples upon receipt at laboratory. Extract PAH from filters. a. Add 5.0 mL of acetonitrile to each culture tube containing a filter. Similarly, add 5.0 mL of acetonitrile to each culture tube containing the media and reagent blanks. Cap the tubes. b. Place capped tubes in an ultrasonic bath for 30 to 60 min. ”

“ SAMPLE PREPARATION: 4. Open filter cassette; transfer filter to ointment jar. 5. Add 4.0 mL acetonitrile; gently swirl for 30 min. 6. Filter each sample using a 5-mL syringe with PTFE syringe filter or Swinney filtration device. Deliver filtrate to a 4-mL vial. CALIBRATION AND QUALITY CONTROL: 7. Prepare at least six working standards daily in the range 0.01 to 1 mg Rotenone per sample. a. Add known amounts of calibration stock solution to acetonitrile in 10-mL volumetric flasks and dilute to the mark. ”

“ NIOSH Manual of Analytical Methods (NMAM) , Fourth Edition POLYNUCLEAR AROMATIC HYDROCARBONS by HPLC: METHOD 5506, Issue 3, dated 15 January 1998 - Page 4 of 9
13. Set HPLC according to manufacturer’s instructions, conditions on page 5506-1, and steps 14 and 15. 14. Inject sample aliquot (10 to 50 μL) . Start mobile phase gradient: a. Linear gradient from 60% acetonitrile/40% deionized water to 100% acetonitrile at 1 mL/min over 20 min. b. Hold at 100% acetonitrile for 20 min. c. Linear gradient to initial condition, 5 min. 15. ”

“ Add 3 mL of 9:1 acetonitrile-methanol to the SPE cartridge. Elute at approx.1-2 mL/m in until the liquid level re aches th e top of the sorbent. C ollect th e eluate in a pre-weighed glass vial. f. Add 3 m L of m etha nol to the SP E ca rtridge. Elute and collect the eluate in the same vial as in step 5.g. g. Use a stream of nitrogen to reduce the volum e to exactly 1.0 mL. Rec onstitute to volum e if necessary by addition of acetonitrile. Determine exact volume using the sample weight and the density of acetonitrile (0.786 g/m L) . 6. Impinger + Filter a. ”

“ Concentration of TEA = 0.2 mM, water = 0.2%, and internal standards = 120 μg/mL. Stableup to 30 days at 0 to 4 °C. 10. Individual analyte stock solutions, 5 mg/mL. Add each analyte to acetonitrile in separate volumetric flasks. Use methylene chloride for benomyl and carbendazim. Use 50/50 v/v methanol/acetonitrilefor formetanate. Store at –12 ± 1 °C. (Solutions are stable up to 30 days.) 11. Calibration stock solution. Combine stock solutions of analytes of interest in a volumetric flask to produce the highest concentration standard (suggest 120 to 480 μg/mL) . ”

“ NOTE: If peak is above the linear range of the working standards, dilute with 30% (v/v) acetonitrile in water, reanalyze, and apply the appropriate dilution factor. Measure peak area or peak height.
CALCULATIONS: 15. 16. ”

“ Water, however, is deleterious to several of the analytes specified in this method (see note A17 above) . Therefore, an acceptable alternative is to inject very small volumes, not greater than 5 μL [31] , of the desorption solvent (acetonitrile in this method) on a high-resolution HPLC column. If it is known that only analytes that are stable in aqueous solutions are to be determinede.g., ( oxamyl and methomyl, but not formetanate or captan) , the desorbates may be diluted with water and larger volumes injected. ”

“ Add acetonitrile to the 50m L m ark.*** 12. Isovaleraldehyde fortification stock solution, 2.40 mg/mL. Dissolve 152 μL of 97% isovaleraldehyde in acetonitrile in a 50-mL volumetric flask. Add acetonitrile to the 50m L m ark.***
EQUIPMENT: 1. Sam pler: Plastic holder containing 0.35 g of 150 to 250-μm (60-100 mesh) silica gel coate d with 1.0 m g of 2,4-dinitrophenylhydrazine which has been acidified. Pressure drop across sampler should be less than 28 inches o f water (7 k Pa) at 1.5 L/m in. ”

“ To the fluid which has passed through, acetate of lead is to be added until precipitation ceases, and the whole, after standing, is to be thrown on a filter. The insoluble meconate of lead remains on the filter, the morphia passing through as acetate. To separate the meconic acid the substance on the filter is to be diffused through water, and sulphuretted hydrogen passed for a time. Sulphide of lead is thus thrown down and may be separated by filtration, the meconic acid remaining in solution. ”

“ It is manifest that, where space is to spare, purifiers containing the materials mentioned in Chapter V. can be added to any portable acetylene apparatus, provided also that the extra weight is not prohibitive. Cycle lamps and motor lamps must burn an unpurified gas unpurified from phosphorus and sulphur; but it is always good and advisable to filter the acetylene from dust by a plug of cotton wool or the like, in order to keep the burners as clear as may be. A burner with a screwed needle for cleaning is always advantageous. ”

“ METHOD 7400, Issue 2, dated 15 August 1994 - Page 5 of 15
acetone into the vaporization chamber with a slow, steady pressure on the plunger button while holding pipet firmly in place. After waiting 3 to 5 s for the filter to clear, remove pipet and slide from their ports. CAUTION:
Although the volume of acetone used is small, use safety precautions. Work in a well-ventilated area (e.g., laboratory fume hood) . Take care not to ignite the acetone. Continuous use of this device in an unventilated space may produce explosive acetone vapor concentrations. ”

“ The absorbing liquid is then poured, and washed out, into a beaker; hydrochloric acid is added to it, and it is boiled in order to expel the liberated chlorine. It is then usual to precipitate the sulphuric acid by adding solution of barium chloride to the boiling liquid, allowing it to cool and settle, and then filtering. The weight of barium sulphate obtained by ignition of the filter and its contents, multiplied by 0.137, gives the amount of sulphur present in the acetylene in the form of sulphuretted hydrogen. ”

“ Acetone is a colourless mobile liquid of pleasant smell, boiling at 56·53°C., and has a specific gravity 0·819 (0°/4°C.) . It is readily soluble in water, alcohol, ether, &c. In addition to its application in the cordite industry, it is used in the manufacture of chloroform (q.v.) and sulphonal, and as a solvent. It forms a hydrazone with phenyl hydrazine, and an oxime with hydroxylamine. Reduction by sodium amalgam converts it into isopropyl alcohol; oxidation by chromic acid gives carbon dioxide and acetic acid. With ammonia it reacts to form di- and tri-acetoneamines. ”

“ Cap the samplers with plastic caps, pack in a manner to insure that the sam plers are kept in the dark, and are s hipped c old (5°C) .
SAMPLE PREPARATION: 5. Place the front and back sorbent sections in separate amber vials. Place the glass wool plug preceding the front section into the vial containing the front sorbent section. Discard the urethane foam plugs. 6. Add 1.0 mL of the acetone/methanol (95:5) solvent into each vial. Securely attach crimp caps to each vial. 7. Plac e ea ch vial on a rotary m ixer fo r 1.5 hours . ”

“ One interesting use of acetone is in connection with the gas acetylene. Of great use both for lighting and also in conjunction with oxygen for welding and cutting metals, this gas suffers from the disadvantage that it cannot be compressed into cylinders and carried about as oxygen can. It can, however, be dissolved in acetone. The cylinders in which it is carried are therefore filled with coke saturated with acetone and then when the acetylene is pressed in it dissolves, coming out of solution again as soon as the pressure is released. ”

“ Acetylene is readily soluble in water, which at normal temperature and pressure takes up a little more than its own volume of the gas, and yields a solution giving a purple-red precipitate with ammoniacal cuprous chloride and a white precipitate with silver nitrate, these precipitates consisting of acetylides of the metals. ”

“ Further details of the valuable qualities of acetone as a solvent of acetylene are given in Chapter XI., but it may here be remarked that the successful utilisation of the solvent power of acetone depends to a very large extent on the absolute freedom from moisture of both the acetylene and the acetone, so that acetone of 99 per cent. strength is now used as the solvent. ”

“ Since acetylene is more soluble in water than any of its diluents or impurities, sulphuretted hydrogen and ammonia excepted, and since the solubility of all gases increases as the pressure at which they are stored rises, the true acetylene in an acetylene holder dissolves in the water more rapidly and comparatively more copiously than the impurities; and thus the acetylene tends to disappear and the impurities to become concentrated within the bell. Simultaneously at the outer part of the seal, air is dissolved in the water ”

“ IMPURITIES OF ACETYLENE.--Combining together what may be termed the carbide impurities and the generator impurities in crude acetylene, the foreign bodies are partly gaseous, partly liquid, and partly solid. They may render the gas dangerous from the point of view of possible explosions; they, or the products derived from them on combustion, may be harmful to health if inspired, injurious to the fittings and decorations of rooms, objectionable at the burner orifices by determining, or assisting in, the formation of solid growths which distort the flame and so reduce its illuminating power ”

“ The working range is 0.1 to 4.8 ppm (0.33 to 17 mg/m3) for a 3-L air sample. However, coadsorbed water vapor will decompose the analyte unless the samples are refrigerated immediately after collection. INTERFERENCES: Acetone, methyl methacrylate and methanol do not interfere with the analysis. Methacrylamide does not elute from the column under the conditions given above. The gas chromatograph must be modified to eliminate contact of analyte with heated glass or metal surfaces. OTHER METHODS: This method was originally designated P&CAM 340 [2] . ”

“ Acetylene is like other gases—explosive when mixed with air in proper proportions, confined, and ignited—and the same precautions should therefore be taken in its use as would be in the handling of coal or water gas, gasoline vapor, etc. As acetylene is very rich in carbon, it will not burn in its pure state without smoking. ”

“ The ether, being freed from acetic acid and alcohol by neutralization and washing, is brought in contact with fused calcium chloride to free it from water, and finally rectified over magnesia. In this manner 36 to 37 lbs. of pure acetic ether are obtained.
Acetic ether is a clear, colorless fluid of a pleasant, etheral odor. It boils at 170.6° F., and at 59° F. its specific gravity is 0.9068. Pure acetic ether dissolves in 11 to 12 parts of water; a content of alcohol or the addition of water increases its solubility. Hence, its solubility in water is a criterion of its purity. ”

“ Acetylene mixed with air and brought in contact with an ignited body explodes even more violently than a mixture of air and coal-gas.
Large quantities of acetylene are generated and stored for oxy-acetylene welding. Acetylene, burning in oxygen, gives an intensely hot flame (about 2000°-3000° C.) , sufficiently hot to melt iron. Although liquid acetylene is unstable, and even the gas, under slight pressure, is also unstable, it may be transported safely if dissolved in acetone. ”

“ Acetic acid, familiar to us in a diluted and flavored form as vinegar, is when concentrated of great value in industry, especially as a solvent. I have already referred to its use in combination with cellulose as a "dope" for varnishing airplane canvas or making non-inflammable film for motion pictures. Its combination [Pg 243] with lime, calcium acetate, when heated gives acetone, which, as may be seen from its formula (C3H6O) is closely related to the other compounds we have been considering, but it is neither an alcohol nor an acid. It is extensively employed as a solvent. ”

“ If the acetylene is to be evolved from a sample of carbide in order to ascertain how much phosphine the latter yields to the gas, about 50 to 70 grammes of the carbide, of the size of peas, are brought into a half-litre flask, and a tap-funnel, with the mouth of its stem contracted, is passed through a rubber plug fitting the mouth of the flask. A glass tube passing through the plug serves to convey the gas evolved to an absorption apparatus, which is charged with about 75 c.c. of a 2 to 3 per cent. solution of sodium hypochlorite. ”

“ Acetone and methanol are flammable and a dangerous fire and explosion risk. They are moderately toxic by ingestion and inhalation. Dimethylacetamide and dimethylformamide are strong irritants to skin and tissue and moderate fire risks. SAMPLING: 1. 2. 3. 4.
Calibrate each personal sampling pump with a representative sampler in line. Break ends of sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.01 to 1 L/min for a total sample size of 15 to 80 L. Cap the samplers. ”

“ NH2, is only known in the form of its salts, the hydrochloride being obtained by the action of ammonia on the hydrochloride of formimido-ethyl ether (A. Pinner, Ber., 1883, 16, p. 357) . Acetamidine, CH3C : (NH) ·NH2, is alkaline in reaction, and readily splits up into acetic acid and ammonia when warmed with acids. Its hydrochloride melts at 163° C., and crystallizes from alcohol in colourless deliquescent prisms. Acetic anhydride converts the base into an acetamino-dimethyl pyrimidine, acetic acid and acetamide being also formed. ”