Sodium sulfate concentration

Purification of luciferin (Rudie etal., 1976). The luciferin fractions from the DEAE-cellulose chromatography of luciferase were combined and concentrated in a freeze-dryer. The concentrated solution was saturated with ammonium sulfate, and extracted with methyl acetate. The methyl acetate layer was dried with anhydrous sodium sulfate, concentrated to a small volume, then applied on a column of silica gel (2 x 18 cm). The luciferin adsorbed on the column was eluted with methyl acetate. Peak fractions of luciferin were combined, flash evaporated, and the residue was extracted with methanol. The methanol extract was concentrated (1 ml), then chromatographed on a column of SephadexLH-20 (2 x 80 cm) usingmethanol asthe solvent. The luciferin fractions eluted were combined and flash evaporated. The residue was... 

Transfer the concentrate into a 200-mL separatory funnel using two portions of 20 mL of n-hexane. Add 100 mL of saturated sodium chloride aqueous solution and extract twice with 100 mL of n-hexane by shaking for 5 min and allow the phases to separate. After dehydration of the n-hexane extract with 10 g of anhydrous sodium sulfate, concentrate the extract to dryness below 40 °C with a rotary evaporator. Transfer the residue with three portions of 5 mL of n-hexane into a glass column containing 10 g of Florisil (deactivated by water at a rate of 1%). Elute with 100 mL of n-hexane-ethyl acetate (9 1, v/v) and then with 100 mL of n-hexane-ethyl acetate (7 3, v/v). Concentrate the second eluate to dryness and dissolve the residue in 10 mL of n-hexane and analysis by gas chromatography/flame thermionic detection (GC/FTD). 

Recovery of IC-0. Combine 20 g of the air-dried soil with 100 niL of a mixed solvent of methanol and 0.1 M ammonium chloride (4 1, v/v) in a 250-mL stainless-steel centrifuge tube, shake the mixture with a mechanical shaker for 30 min and centrifuge at 8000 r.p.m. for 2 min. Filter the supernatant through a Celite layer (1-cm thick) under reduced pressure into a 500-mL flask. Add 100 mL of mixed solvent of methanol and 0.5 M sodium hydroxide solution (4 1, v/v) to the residue and then extract and filter in the same manner. Combine the flltrates and concentrate to approximately 40 mL on a water-bath at ca 40 °C by rotary evaporation. Add 10 mL of distilled water and adjust the pH of the aqueous layer to 7 with hydrochloric acid. Transfer the aqueous solution into a 200-mL separatory funnel and shake the solution with 50 mL of mixed solvent of dichloromethane and acetone (1 1, v/v) for 5 min. Discard the mixed solvent and adjust the pH of the aqueous layer to 1.5 with hydrochloric acid. Extract the solution with three portions of 50 mL of diethyl ether. Combine the diethyl ether extracts and dry over anhydrous sodium sulfate. Concentrate to dryness on a water-bath at ca 40 °C by rotary evaporation. 

Cleanup procedure for IC-0. Dissolve the residue with 10 mL of pH 5 phosphate buffer solution and apply the solution to the top the Sep-Pak Cig Env. column pretreated with 10 mL each of methanol and distilled water. Discard the passed solution and elute IC-0 with 15 mL of a second buffer solution. Add 35 mL of distilled water and adjust the pH of solution to 1.5 with hydrochloric acid. Extract the solution with three portions of 50 mL of diethyl ether. Combine the diethyl ether extracts and dry over anhydrous sodium sulfate. Concentrate to dryness on a water-bath at ca 40 °C... 

Extracts of these fat samples were treated with sodium sulfate-concentrated sulfuric acid mixture and fuming acid by the method described by Schechter et al. 5) in order to separate the organic-chlorine compound from the fatty materials. An infrared spectrum from 7 to 15 microns on carbon disulfide solutions of the residues from the fat qualitatively identified the organic-chlorine compound as toxaphene. All the bands of toxaphene in this spectral region were plainly seen in the treated steer extract, whereas none of the absorption bands were visible in the untreated steer extract. 

Picer and Picer [357] evaluated the application ofXAD-2, XAD-4, and Tenax macroreticular resins for concentrations of chlorinated insecticides and polychlorinated biphenyls in seawater prior to analysis by electron capture gas chromatography. The solvents that were used eluted not only the chlorinated hydrocarbons of interest but also other electron capture sensitive materials, so that eluates had to be purified. The eluates from the Tenax column were combined and the non-polar phase was separated from the polar phase in a glass separating funnel. Then the polar phase was extracted twice with n-pentane. The -pentane extract was dried over anhydrous sodium sulfate, concentrated to 1 ml and cleaned on an alumina column using a modification of the method described by Holden and Marsden. The eluates were placed on a silica gel column for the separation of PCBs from DDT, its metabolites, and dieldrin using a procedure described by Snyder and Reinert [359] and Picer and Abel [360]. 

Crude Copper Phthalocyanine Blue is stirred in 60% sulfuric acid and the thus obtained sulfate hydrolyzed with water. Subsequent filtration affords the 7-phase. It is also possible to knead crude Copper Phthalocyanine Blue with salt (sodium sulfate), concentrated sulfuric acid, and a third agent, which may be an alcohol, a polyalcohol, or one of the corresponding organic esters [19]. A third option is to stir a-Copper Phthalocyanine Blue with 30% sulfuric acid and glycol monobutyl-ester or the corresponding ethyl ester or tetrahydrofuran [20],... 

Water Extracted with dichloromethane/hexane, dry with sodium sulfate, concentrated. GC/ECD 0.05 ppb No data ASTM 1988... 

Water Acidified water. Extracted through Empore Disk with ethyl acetate followed by dichloromethane. Dried with sodium sulfate, concentrated. GC/MS No data 126-128 Kraut-Vass and Thoma 1991... 

Sox h let extracted with 1 1 hexane/acetone. Dried extracts with sodium sulfate, concentrated. Solvent exchanged to MTBE. 

Water Extract serial with methylene chloride at pH >11 (pH 7 for capillary column) and pH 2 analyze extracts separately for packed column, combined for capillary column dry over anhydrous sodium sulfate concentrate inject GC/MS 1-10 pg/L 70-81 Eichelberger et al. 1983... 

Waste water Add stable isotopically labeled analogs of the compounds to 1 L of waste-water sample extract sample at pH 12-13, then at pH <2, with methylene chloride using continuous extraction techniques dry extract over sodium sulfate concentrate add internal standard inject GC/MS 10 pg/L NR EPA 1990b (Method 1625)... 

The surrogate compounds were mono-, tetra-, octa-, deca- C-PCBs, dg-naphthalene, C-PCP and C-phenol. The soil samples were dried with Na2S04 (60 g) and then Soxhlet extracted with hexane acetone (9 1) for 16 h. The extract was dried with sodium sulfate, concentrated, and split. While one portion was held for other analyses, the other portion was placed on a 3% deactivated silica gel column and eluted with increasing solvent polarity systems [hexane, followed by methylene chloride hexane (1 1), and then methylene chloride acetone (95 5)]. The extracts were combined and reduced to 1 mL, split and two internal standards added (tetrafluorobiphenyl and di2 Chrysene). The extracts were chromatographed on a 15-m DB-5 fused silica capillary column and detected with flame ionization (FID). Sludge samples were extracted according to the EPA sludge protocol (2) developed at Midwest Research Institute. 

Wastewater, municipal and industrial Add isotope-labelled analogue extract with dichloromethane dry over sodium sulfate concentrate GC/MS lOpg/L Environmental Protection Agency (1999a) [Method 1625]... 

Soil Addition of 10 ml water and deuterated standards to 50 g of soil followed by equilibration for 1 h. Sonication 3 times with acetone/ hexane. Phase separation followed by water removal using sodium sulfate, concentration using K-D, and nitrogen blow-down. Spiking with phenanthrene-... 

The chloroform layer is dried over sodium sulfate, concentrated to dryness in vacuo, and the residue recrystallized from isopropyl ether, 3.78 g, melting point 81°C to 83.5°C. 

A crystallizer contains 6420 lb of aqueous solution of anhydrous sodium sulfate (concentration 29.6 wt %) at 104 °C. The solution is cooled to 20 °C to crystallize out the desired Na2SC>4. 10 H2O. The remaining solution (the mother liquor) is found to contain 16.1 % anhydrous sodium sulfate. What is the weight of this mother liquor. 

When the period of refluxing is shorter, the yield is materially decreased. The first methyl group reacts easily but the second only with considerable difficulty. A longer period of refluxing does not give much larger yields. As the sodium sulfate concentration increases, the dimethyl sulfate hydrolyzes less readily. 

The remaining extract was filtered through a bed of sodium sulfate, concentrated to low volume in a Kudema Danish evaporator, and then rinsed onto a column of activated Florisil. The Florisil column was eluted successively with 6 and 15% diethyl ether in hexane. Both eluates were concentrated to 0.2- to 0.3-ml. volumes to provide samples for identification by gas chromatography. The activity of the Florisil was checked by chromatographing a solution of hexane containing aldrin, heptachlor epoxide, dieldrin, endrin, and the n-butyl ester of 2,4-D. The column was judged acceptable when the first three compounds appeared in the 6% eluate and the last two in the 15% eluate. 

The reaction mixture is placed in a separatory funnel the aqueous phase is separated and extracted twice with chloroform (CHCI3). The organic phases are combined, washed twice with water, and dried with anhydrous sodium sulfate overnight. After filtration to remove sodium sulfate, concentration under vacuum affords a residue, which is heated (5 mm, 130°C oil bath) to remove and recover excess di-tert-... 

New interest in the nature of the constituent serum proteins resulted from the introduction of the sodium sulfate fractionation scheme by Howe (H24, H25). This was a technical advance because, unlike ammonium sulfate, sodium sulfate need not be removed prior to nitrogen analysis, the only accurate available means at that time of determining protein. Howe (H24) observed three ranges of sodium sulfate concentration at which an increase in molarity of 0.05 in a 1 30 dilution of calf serum failed to produce the expected increase in precipitation. One of these critical concentrations occurred at 1.45-1.50 M and was thought to indicate complete globulin precipitation. 

Adjustment to pH <11.0 extraction with methylene chloride drying with sodium sulfate concentration... 

Table 8.2 Recoveries of some organic compounds in a clay and peat soil using a screening procedure. Extraction after wetting with ammonium chloride solution and extraction at pH 1 and pH 10 using acetone followed by petroleum ether/dichloromethane. Extracts are dried with anhydrous sodium sulfate, concentrated and injected in a GC-MS. Herbicides and chlorophenols are methylated using trimethylsulfoniumhydroxide (Traag etal. 1997)...

The confirmatory assay for flunixin in bovine liver utilized capillary gas chromatography/mass spectrometry to isolate and confirm the structure of the marker residue. The extraction procedure is similar to that for the surveillance assay, except that following extraction of the acidified aqueous layer, the organic layer is dried with sodium sulfate, concentrated to dryness under nitrogen, derivatized with trimethylsilane, and a portion of the derivatized extract analyzed by capillary gas... 

Reaction with phosphorus oxychloride 806 Carbon disulfide (18 ml, 0.3 mole) is dropped into a stirred solution of an amine (0.3 mole) and anhydrous triethylamine (126 ml, 0.9 mole) in anhydrous ether (150 ml) at —5° with aromatic amines the mixture is set aside overnight. Then a solution of phosphorus oxychloride (28 ml, 0.3 mole) in anhydrous ether (30 ml) is dropped in, with stirring, at —10° to —5°. Next day the precipitated triethylammonium chloride is filtered off and stirred thoroughly with two portions of ether. The ethereal solutions are extracted with sodium hydrogen carbonate solution and with water, dried over sodium sulfate, concentrated, and fractionated. Yields are about 60%. 

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