Equipment chromatographic column

In a dry, 1-1., two-necked flask, equipped with a mechanical stirrer and a reflux condenser fitted with a drying tube, are placed 17.8 g. (0.100 mole) of anthracene (Note 1), 27.2 g. (0.202 mole) of anhydrous cupric chloride (Note 2), and 500 ml. of carbon tetrachloride (Note 3). The reaction mixture is stirred and heated under reflux for 18-24 hours. The brown cupric chloride is gradually converted to white cuprous chloride, and hydrogen chloride is gradually evolved. At the end of the reaction the cuprous chloride is removed by filtration, and the carbon tetrachloride solution is passed through a 35-mm. chromatographic column filled with 200 g. of alumina (Note 4). The column is eluted with 400 ml. of carbon tetrachloride. The combined eluates are evaporated to dryness to give 19-21 g. (89-99%) of 9-chloroanthracene as a lemon-yellow solid, m.p. 102-104° (Note 5). Crystallization of the product from petroleum ether... 

Chromatographic columns (glass with stopcock and solvent reservoir, 10-mm i.d.) Fused-silica capillary column, DB-1701, 60 m x 0.32-mm i.d., O.lS-qm film thickness (14% cyanopropylphenyl)methylpolysiloxane Varian 3400 gas chromatograph equipped with a temperature-programmed SPI injector, a Varian 8100 autosampler, and a Varian Saturn II lontrap mass spectrometer Centrifuge vials, 10- and 250-mL Evaporation flasks, 100- and 250-mL Separatory funnel, 250-mL... 

The system used by these workers consisted of a Microtek 220 gas chromatograph and a Perkin-Elmer 403 atomic absorption spectrophotometer. These instruments were connected by means of stainless steel tubing (2mm o.d.) connected from the column outlet of the gas chromatograph to the silica furnace of the a.a.s. (Fig. 13.2). A four-way valve was installed between the carrier gas inlet and the column injection port so that a sample trap could be mounted, and the sample could be swept into the gas chromatographic column by the carrier gas. The recorder (lOmV) was equipped with an electronic integrator to measure the peak areas, and was simultaneously actuated with the sample introduction so that the retention time of each component could be used for identification of peaks. 

Level two requires a verification of the effect of more severe changes in conditions, such as the use of chromatographic columns from different manufacturers or the substitution of different equipment, and should be performed in a different laboratory . This second level can be considered as being equivalent to the US Pharmacopeia (USP) definition. 

PQ should be performed on a daily basis or whenever the instrument is used. The test frequency not only depends on the stability of the equipment but on everything in the system that may contribute to the results. For a liquid chromatograph, this may be the chromatographic column or a detector s lamp. The test criteria and frequency should be determined during the development and validation of the analytical method. 

High-performance liquid chromatograph (HPLC e.g., Waters Chromatography) equipped with column heater, solvent pump, UV detector (set at 210 nm), integrator, autosampler, and (for manual injection) a 10-pl sample loop 15 x 0.46-cm YMC-ODS-AQ analytical column (AQ12S031546WT, Waters Chromatography)... 

The sample extract is injected into a HPLC containing a reverse phase HPLC column. The analytes are identified by comparing their retention times with that of the standard. A more reliable and confirmatory test is to use a mass spectrometer equipped with a particle beam and interfaced to the HPLC column. The compounds are identified from their mass spectra as well as retention times. The chromatographic column and conditions are described below. 

A second alternative to the conventional chromatographic column is to use a narrower column bore, typically 1-3 mm ID. For these narrow-bore columns, the primary advantage is an increase in mass sensitivity [44] along with reducing the volume of the eluent. In contrast to the 1-2-mm-ID columns the 3.0-mm-ID columns can be used with conventional HPLC equipment. The most likely role for narrow-bore columns will be in pharmaceutical analysis as an interface to detectors such as a mass spectrometer. ... 

Other usual equipment for work-up and isolation, such as rotary evaporator, separatory funnel, and chromatographic column... 

Volatile additives for vulcanised or unvulcanised rubbers can be accurately identified by TG or by controlled heating of a test sample in a sealed vial equipped with an overhead collecting headspace, transferring the heated volatile substances to a chromatographic column and analysing the separated volatile components emerging from the chromatograph column by various selective analytical detectors. Several illustrative examples were mentioned before. 

Another factor that contributes to Rs is the plate count N. However, we have seen in section 1.5 that optimization through an increase in N is expensive, not only in terms of equipment and columns, but also in terms of analysis time. Therefore, as long as the shape of the peaks and the plate height (length of the column divided by N) are satisfactory, we should not rely on the number of plates for optimization, unless as a last resort. Methods which may be used to optimize the chromatographic system with respect to the required number of plates will be described in chapter 7. 

Phillips and Timms [599] described a less general method. They converted germanium and silicon in alloys into hydrides and further into chlorides by contact with gold trichloride. They performed GC on a column packed with 13% of silicone 702 on Celite with the use of a gas-density balance for detection. Juvet and Fischer [600] developed a special reactor coupled directly to the chromatographic column, in which they fluorinated metals in alloys, carbides, oxides, sulphides and salts. In these samples, they determined quantitatively uranium, sulphur, selenium, technetium, tungsten, molybdenum, rhenium, silicon, boron, osmium, vanadium, iridium and platinum as fluorides. They performed the analysis on a PTFE column packed with 15% of Kel-F oil No. 10 on Chromosorb T. Prior to analysis the column was conditioned with fluorine and chlorine trifluoride in order to remove moisture and reactive organic compounds. The thermal conductivity detector was equipped with nickel-coated filaments resistant to corrosion with metal fluorides. Fig. 5.34 illustrates the analysis of tungsten, rhenium and osmium fluorides by this method. 

It was estimated that the total equipment cost was 1.69 million for this process. The major portion of this equipment cost was attributed to the chromatographic columns which was about 49%. The installation of this... 

The basic experimental equipment for FFF is, except for the channel and its support, in general identical to the equipment used for liquid chromatography. It is usually composed of a solvent reservoir, a pump, and an injection system the chromatographic column is replaced by the FFF channel, followed by a detector. The FFF channel can require additional supporting devices, such as a centrifuge for sedimentation FFF or a power supply, and other electronic regulation devices for electrical FFF. If necessary, this basic equipment is complemented by a flow meter at the end of the separation system. For special semipreparative purposes, a fraction collector can be attached to the system. 

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