Teflon coated filters

The typical method implemented is the installation of fabric filters. Teflon coated fiberglass or Nomex (nylon), in a gas cleaning equipment, commonly referred to as a baghouse. These devices are located downstream with respect to the cyclone and generally the gas is cooled before being treated. 

B. 4-Nonylbenzoic acid. A 500-mL, round-bottomed flask equipped with a Teflon-coated magnetic stirbar and a reflux condenser is charged with 4-nonylbenzoic acid methyl ester (10.07 g, 38.37 mmol), 100 mL of methanol (Note 1), and 96 mL of 1M aqueous NaOH. The resulting mixture is heated at reflux for 18 hr and then allowed to cool to room temperature. The reaction mixture is carefully acidified by addition of 200 mL of 1M aqueous HC1, and the resulting solution is transferred to a separatory funnel and extracted with four 250-mL portions of ethyl acetate. The combined organic layers are dried over Na2S04, filtered, and concentrated by rotary evaporation at reduced pressure. The residue (ca. 9.5 g) is recrystallized from 70 mL of hexanes to give 8.32-8.35 g (87-88%) of 4-nonylbenzoic acid as a white solid (Notes 6, 7). 

A mixture of fluorene (1.5 g, 9 mmol), alumina-supported copper(II) bromide (30 g), and carbon tetrachloride (80 ml) was placed in a 200 ml round-bottomed flask and stirred with a Teflon-coated magnetic stirring bar at 80°C for 5 h. The product mixture was filtered, and the spent reagent was washed with carbon tetrachloride (30 ml). Evaporation of solvent from the combined filtrate under reduced pressure yielded 2.84 g (97 %) of 2.7-dibromofluorene as a pale yellow solid having iH NMR and IR spectra identical with those of an authentic sample, mp 157-159°C (lit. mp 162-163°C (ref. 17)). The purity was > 96 % (GC). 

HPLC methods with fluorescence detection have also been developed for the determination of nitro-policyclic aromatic hydrocarbons (PAHs) (among which 9-nitroanthracene and 1-nitronaph-thalene) [238] in atmosphere. Samples have been collected in a standard high-volume sampler with a Teflon-coated glass fiber filter, and the Soxhlet extraction was performed with dichloromethane as the solvent. RP HPLC/UV techniques are used for the determination of aldehydes, ketones, and carbonylic compounds after derivatization with DNPH [239],... 

A 100-mL round-bottomed flask containing a Teflon-coated magnetic stirring bar is charged with a solution of 0.45 g (1 mmol) of (pentafluorophenyl)(tetra-hydrothiophene)gold(I) in 50 m L of diethyl ether, to which is added, 0.15 mL (1 mmol) of pdma. After stirring for 5 min at room temperature formation of a white precipitate is observed. Concentration of the solvent to 10 mL causes white crystals to precipitate, which are filtered, washed with two lOmL portions of hexane, and dried. Yield 0.52 g (80%). 

This reaction may be carried out in air. A 500-mL capacity Erlenmeyer flask containing a large Teflon-coated stirring bar is charged with a filtered... 

For cis-[RuCl2(trpy)(PMe3)], 4, the solvent is reduced to a volume of 3-5 mL with a rotary evaporator and slowly dripped into a 500-mL Erlen-meyer flask equipped a teflon-coated magnetic stir bar containing rapidly stirring hexanes (200 mL). A red-violet solid is vacuum filtered, washed with hexanes (3x5 mL), and air dried. Yield 0.070 g (0.15 mmol, 100%) of ris-[RuCl2(trpy)(PMe3)], 4. 

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