Chromatography columns used

Z. Fiu and J. B. Phillips, Farge-volume sample introduction into narrow-hore gas chromatography columns using thermal desorption modulation and signal averaging , /. Microcolumn Sep. 2 33-40 (1990). 

Performance Characterization of Liquid Chromatography Columns Using Reduced Parameters... 

Table 15.9 lists the materials and consumables usage for this composite process, showing water consumption ranges from over 3000 to almost 7000 kg per kg mAb produced and consumables from 2 to 8 kg per kg of mAb. Water usage in the cell culture step makes up from 20 to 25% of the total whereas the three chromatography columns use over 50% of the total. The breakdown of water usage for the optimized, large-scale process is shown in Table 15.10. 

A retention gap is used to improve peak shapes under certain conditions. If you introduce a large volume of sample (>2 pL) by splitless or on-column injection (described in the next section), microdroplets of liquid solvent can persist inside the column for the first few meters. Solutes dissolved in the droplets are carried along with them and give rise to a series of ragged bands. The retention gap allows solvent to evaporate prior to entering the chromatography column. Use at least 1 m of retention gap per microliter of solvent. Even small volumes of solvent that have a very different polarity from the stationary phase can cause irregular solute peak shapes. The retention gap helps separate solvent from solute to improve peak shapes. 

NOTE Details about chromatography columns used for carotenoids are contained in unit F2.3. 

A reversed-phase HPLC Cl8 or C30 narrow-bore column is typically used for LC/MS with APCI. Details about chromatography columns used for carotenoids are contained in unit F2.3. For most APCI systems, the optimum flow rate into a mass spectrometer or tandem mass spectrometer equipped with APCI, as controlled by a syringe pump or HPLC pump, is usually between 100 and 300 pl/min, which is ideal for narrow-bore HPLC columns. Larger diameter columns should be used with a flow splitter postcolumn to reduce the solvent flow into the mass spectrometer. For example, if a 4.6 mm i.d. column was used at a flow rate of 1.0 ml/min, then the flow must be split postcolumn 5 1 so that only 200 pl/min enters the mass spectrometer. 

Z. Liu and J. B. Phillips, Sample introduction into a 5 pan i.d. capillary gas chromatography column using an on-column thermal desorption modulator , J. Microcolumn Sep. 1 159-162(1989). 

Gas Chromatography Column Use a stainless steel column, or equivalent, 3 m x 3.2 mm (od), packed with 10% Carbowax 20 M on 80/100-mesh Gas Chrom 2, or equivalent. After packing and before use, condition the column overnight at 200°, using a helium flow of 25 mL/min. 

Prepare a silica gel chromatography column using dichloromethane, and load the column by dissolving the residue in the minimum volume of dichloromethane. Run the column with dichloromethane/methanol (199 1, v/v) and the desired dithiol elutes with an of 0.5 (99 1, CH2CI2-MeOH, v/v). Evaporate the eluates containing this material to yield a colourless oil... 

Prepare a chromatography column using silica (100 g) and petroleum (b.p. 40-60°C). Dissolve the residue from evaporation in diethyl ether (5 mL)... 

Waste water Addition of HN03 to sample and evaporation redissolution in water (pH should be 2) separation on ion chromatography column using TPPS4/PAR/NaCI/Na2B407-Na0H as post-column derivatization agent Spectro- photometry 50 g/L No data Yan et al. 1989... 

Whole oil gas chromatography of the oil and condensate samples was performed using a Hewlett Packard 7673 Autosampler to inject 0.1 pi of whole oil spiked with internal standard into a split/splitless injector of a Hewlett Packard 5890 GC equipped with flame ionization detection. Products were swept into a 60 m J W Scientific DB-1 capillary gas chromatography column using helium as the carrier gas under constant flow conditions. The oven temperature program started at 30 °C, held for 5 min, ramped to 320 °C at 3°C/min, and held for 20 min. The injector was held at a constant 275 °C. 

The chromatography columns used are Berger Instruments Amino, Cyano, and Diol in 6-p particle size with a 21.2 x 150mm format. The standard gradient elution methods employed are 5-50% methanol in... 

After cross-linking polymerization, the grounded power was packed in chromatography columns using an acetonitrile-acetic acid solution then, assessment of affinity was examined for cinchonidine target molecule. Preliminary results proved that the prepolymer method presents potential utilization as an artificial receptor. 

Compound 6 Diethjd azodicarboxylate (DEAD) (40 mg, 0.23 mmol) was added to a solution of compound 4 (280 mg, 0.16 mmol), compound 5 (81 mg, 0.21 mmol) and triphenylphosphine (60 mg, 0.23 mmd) in 3 ml THF. The mixture was stirred at room temperature for 3 h. After the solvent was removed with a rotary evaporator, the crude product was purified by a silica chromatography column using hexane / ethyl acetate (2 / 1) as the eluent to give... 

Ai-aryl benzamide (1 0.20 mmol), [RuCl2(pcymene)]2 (0.02 mmol), 0-benzoyl hydroxylamine (2 0.60 mmol), and K2CO3 (0.40 mmol) dissolved in acetone (1 mL) was stirred in a 25 mL Schlenk tube at room temperature under argon atmosphere for 36 h. Upon completion, the reaction mixture was diluted with ethyl acetate and filtered through a small pad of Celite. The filtrate was concentrated in vacuo and purified by a silica gel packed flash chromatography column, using ethyl acetate/hexane as the eluent to furnish pure substituted aryl/heteroaryl amine 3. All the products were characterized by spectral methods. 

To a solution in MeOH/THF (1 1, 160lmol ) of the glycoside, a IN solution of lithium hydroxide (30 equiv) was added at 0 °C. After 1 h of stirring at 0 °C and then 16 h at room temperature, the saccharide was purified over a size-exclusion LH-20 Sephadex chromatography column using MeOH/DMF (9 1) as eluant to give the... 

Experimentally, an inertness/reactivity of Cn was supposed to be investigated by studying its volatility with respect to that of Hg and Rn as adsorption on a gold surface (gold plated detectors) of the chromatography column used in gas-phase chromatography experiments [201-203] ( Gas-Phase Chemistry of Superheavy Elements ). The questions to the modern electronic structure theory, therefore, were Is Cn metallic in the solid state, or is it more like a solid noble gas What is its Af/sut How volatile and reactive towards gold is the Cn atom in comparison with Hg and Rn ... 

The Jordi Reversed Phase - DVB liquid chromatography columns use a highly crosslinked divinylbenzene polymer packing material. These coliunns give very good resolution for mixture of oleamide, stearamide, and erucamide, using water and acetonitrile as a mobile phase. 

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