Titanium columns

At the present time the titanium column shown in figure 4 is installed in a Pu-test cycle at Karlsruhe with a throughput of about 400 g Pu/h, where the electro-reductive Pu backextrac-tion can be tested and compared with the competitive procedure using hydroxylamine nitrate (HAN) as reducing agent. 

Fig. 1.16 Comparative thermochromatograms of some alkali, alkaline earth and rare earth metals in a titanium column [77], Conditions open titanium column, 4.5 mm i.d., average temperature gradient 57 K cm-1, duration of run 15 min carrier gas helium, 44 cm3 min 1 reagent 0.5 mg of Ca evaporated per run.

Stainless-steel (type 316) columns do not have these disadvantages of copper, aluminium and iron tubes and are very suitable. In most HPLC applications, 316 stainless-steel column tubes can be used without difficulty. When the chemical inertness is insufficient, the 316 stainless-steel column can be replaced with the more expensive but more inert tantalum column tubes (Siemens). When very strongly acidic mobile phases have to be used, 316 stainless-steel columns are less suitable. For such instances, sometimes home-made titanium columns, including titanium terminators and injection systems, have been applied successfully. ... 

The same observation can be made for the imido complexes M=NR, an extremely rich family. Indeed, nitrogen being not as electronegative as oxygen, the above constraints are less severe. Thus the M=NR family spreads from the titanium column to the iron one and even to iridium. Here again, there is a predilection for d complexes, but it is possible to raise the NNBE until d, for instance in Cp Ir — NAr, with a linear geometry, below. 

Since the heaviest actinides are available only in trace amounts, unusual experimental approaches must be used in order to characterize their elemental state properties. Recently, Zvara and co-workers compared the evaporation rates of trace amounts of Es, Fm, and Md from molten La with those of Ce, Eu, Yb, Am, and Cf in order to obtain information on their metallic states [13], while Huebener compared the thermochromatographic behavior of Es, Fm, and Md evaporated from molten La in titanium columns with those of Na, Sc, Sm, Eu, Yb, Bk, and Cf [14]. From their results, both authors concluded that Es, Fm, and Md prefer the divalent metallic state. 

Helium [7440-59-7] M 4.0. Dried by passage through a column of Linde 5A molecular sieves and CaS04, then passed through an activated-charcoal trap cooled in liquid N2, to adsorb N2, argon, xenon and krypton. Passed over CuO pellets at 300° to remove hydrogen and hydrocarbons, over Ca chips at 600° to remove oxygen, and then over titanium chips at 700° to remove N2 [Arnold and Smith 7 Chem Soc, Faraday Trans 2 77 861 1981]. 

This was converted to its imine with methylamine catalyzed by titanium tetrachloride and then sodium borohydride reduction produced 17 as a mixture of diastereomers. This was resolved by column chromatography to give sertraline [5]. Dextrorotatory cis sertraline is substantially more potent than its isomers. 

In the titanium dioxide production plant where the chlorine process is employed, the wastewater from the kiln, the distillation column, bottom residue, and those from other parts of the plant first settle in a pond. The overflow from this pond is neutralized with ground calcium carbonate in a particular reactor, while the scrubber wastewater is neutralized with lime in another reactor. The two streams are sent to a settling pond before being discharged. 

General Considerations. The following chemicals were commercially available and used as received 3,3,3-Triphenylpropionic acid (Acros), 1.0 M LiAlH4 in tetrahydrofuran (THF) (Aldrich), pyridinium dichromate (Acros), 2,6 di-tert-butylpyridine (Acros), dichlorodimethylsilane (Acros), tetraethyl orthosilicate (Aldrich), 3-aminopropyltrimethoxy silane (Aldrich), hexamethyldisilazane (Aldrich), tetrakis (diethylamino) titanium (Aldrich), trimethyl silyl chloride (Aldrich), terephthaloyl chloride (Acros), anhydrous toluene (Acros), and n-butyllithium in hexanes (Aldrich). Anhydrous ether, anhydrous THF, anhydrous dichloromethane, and anhydrous hexanes were obtained from a packed bed solvent purification system utilizing columns of copper oxide catalyst and alumina (ether, hexanes) or dual alumina columns (tetrahydrofuran, dichloromethane) (9). Tetramethylcyclopentadiene (Aldrich) was distilled over sodium metal prior to use. p-Aminophenyltrimethoxysilane (Gelest) was purified by recrystallization from methanol. Anhydrous methanol (Acros) was... 

After adjusting to 2 mol 1 1 in hydrochloric acid, 500 ml of the sample is adsorbed on a column of Dowex 1-XS resin (Cl form) and elution is then effected with 2 M nitric acid. The solution is evaporated to dryness after adding 1M hydrochloric acid, and the tin is again adsorbed on the same column. Tin is eluted with 2 M nitric acid, and determined in the eluate by the spectrophotometric catechol violet method. There is no interference from 0.1 mg of aluminium, manganese, nickel, copper, zinc, arsenic, cadmium, bismuth, or uranium any titanium, zirconium, or antimony are removed by ion exchange. Filtration of the sample through a Millipore filter does not affect the results, which are in agreement with those obtained by neutron activation analysis. 

The strontium titanium sulfides, SrvTiSwhich exist between the x values of 1.05 and 1.22, contain interpenetrating rods of structure, both of which are modulated. In idealized Sr,TiS i, face-sharing TiS6 octahedra (Fig. 4.38a) form columns with a repeat... 

Titania is being examined for use as a base material for bonded stationary phases because of its stability and its ability to separate bases under normal-phase conditions.Other researchers are investigating silica that has been surface modified with titanium oxide followed by the immobilization of poly(methyloctylsiloxane). These columns show promise for routine chromatographic analyses, but more research needs to be performed to evaluate the best manufacturing methods. 

Liposomes (SUVs) were prepared by probe sonication according to standard procedures (31) in the presence of STPP. A mixture of lecithin, cholesterol, and STPP (PC/Ch/STPP = 65/15/20, molar ratio final total lipid 25 mg/ mL) was dissolved in chloroform followed by removal of the organic solvent using a rotary evaporator. After adding 5 mM HEPES (pH 7.4) to the dry lipid film, the sample was probe sonicated with a Sonic Dismembrator (Model 100, Fischer Scientific) at a power output of approximately 10 W for 30 minutes. To remove any titanium particles, which have been shed from the tip of the probe during sonication, the sample was centrifuged for 10 minutes at 3000 X g. The formed liposomes were separated from free, i.e., nonincorporated, STPP by gel filtration chromatography on a Sephadex G-15 column. 

Carbon steel, stainless steel, aluminum, tantalum, titanium, and zirconium are used for both loose-fill and structured metal packing. All have reportedly been involved in packing fire incidents. Titanium, in particular, has been involved in a number of column fires. 

The transeinsteinium actinides, fermium (Fm), mendelevium (Md), nobelium (No), and lawrencium (Lr), are not available in weighable (> ng) quantities, so these elements are unknown in the condensed bulk phase and only a few studies of their physicochemical behavior have been reported. Neutral atoms of Fm have been studied by atomic beam magnetic resonance 47). Thermochromatography on titanium and molybdenum columns has been employed to characterize some metallic state properties of Fm and Md 61). This article will not deal with the preparation of these transeinsteinium metals. 

At higher temperatures, zirconium dioxide and titanium dioxide supports gave much greater stability along with polymer-based supports [100,101] based on polystyrene-divinyl benzene (PS-DVB) such as PLRP-S noted in Table 9.5. PS-DVB supports have been reported to give a serious column bleed at 250°C [66]. Polybutadiene (PBD) modified zirconia columns have been used at temperatures up to 300°C and carbon-coated zirconia has been used at temperatures up to 370°C [66]. Applications have included the separation of steroids [73] and herbicides [102].The specific order of column bleed varied depending on the detection method as shown in Table 9.5. 

Aluminum, copper, nickel, and their alloys unalloyed titanium A-6 (a) No additional requirements A-6 (b) No additional requirements unless filler metal composition is outside the range for base metal composition then test per column B-6 B-6 Designer shall be assured by suitable tests [see Note (4)] that base metal, weld deposits, and HAZ are suitable at the design min. temp. 

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