Acid mist produced during

Gas from the absorber contains some sulfuric acid mist formed during the cooling step plus a small amount of liquid entrained from the absorption tower. Removal of diis mist is the key step in the process. In the Monsanto Cat-Ox prototype plant, the mist is removed by a fiber-packed cartridge type eliminator that produces an effiuent gas containing less than 1.0 mg 100% H2SOyscf. This amounts to about 10 ppm of acid as misL The v r pressure of sulfuric acid at 22S°F contributes another 11 ppm so the total quantity of sulfuric acid in the... 

Occasionally mist problems occur during startup when the concentration of acid used for air drying is too low or while oleum is being produced in the first absorber, both of which promote aerosol formation [60]. These causes are usually intermittent and discharge prevention relies on mist control equipment. 

Solvent removal and ionization are combined during electrospray in which the HPLC eluate (at flow rates as high as 1 mL/min) is sprayed through a capillary electrode at high potential to form a fine mist of charged droplets at atmospheric pressure. As the solvent evaporates, gas-phase sample ions are formed. The first application of electrospray LC-MS to the analysis of retinoids was reported by van Breemen and Huang (308). Retinoic acid, retinol, retinal, and retinyl acetate were analyzed without derivatization using a C30 reversed-phase HPLC column. Retinoic acid formed abundant deprotonated molecules, [M-H] , with a limit of detection of 23 pg injected on-column. Positive ion electrospray produced an abundant protonated molecule for retinal, and a base peak of m/z 269 was observed for retinol and retinyl acetate, which corresponded to elimination of water or acetic acid, respectively, from their protonated molecules. The limits of detection of retinal, retinol, and retinyl acetate were 1.0 ng, 0.5 ng, and 10 ng, respec-... 

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