HPLC pumps

Fractogel EMD BioSEC (S) a Superformance column 600-26 packed with Fractogei EMD BioSEC (S) (V, 318.5 mi 600 mm bed height) was connected to an external pressure gauge (0.1 -6.0 bar), and a HPLC pump. The linear flow rate was increased successively from 10 up to 100 cm/hr and the pressure drop was measured. A pressure drop of I bar was reached at a linear flow rate of approximately 25 cm/hr. (B) The same experiment was performed using a Superformance 1000-200 preparative column (200 mm i.d.) with a bed volume of 20 liter (63 cm bed height) and a maximum flow rate of 50 cm/hr. A pressure drop of I bar was reached at a linear flow rate of approximately 17 cm/hr. 

For acrylate polymers with higher levels of carboxylic acids, THF can be modified by the addition of acids such as acetic, phosphoric, or trifluoroacetic. Levels as high as 10% acetic acid are considered acceptable by most manufacturers for their styrene/DVB columns. If such a modified mobile phase is used, it may need to be premixed rather than generated using a dynamic mixing HPLC pump because on-line mixing often leads to much noisier baselines, particularly when using a refractive index detector. 

Most high-performance liquid chromatography (HPLC) pumps can be used in HOPC. The back pressure rating should be at least several thousand pounds per square inch (a few hundred kg/cm ). A type of pump that does not allow bypassing the pressure transducer or a pulse damper, if it is installed, must not be used. The dead volume should be as small as possible. Pumps with a single plunger are better than those with two plungers. 

Hotter and Balannec published one of the first real proposals to use SMB as a production tool for the pharmaceutical industry, and thus to scale down a process already used on a production scale [29]. The first commercially available plant (Licosep) SMB system was offered by Separex in 1991 and was exhibited for the first time in June 1991 during the Achema Exhibition. The system consisted of 24 stainless steel columns with adjustable lengths between a few centimeters up to almost 1 meter, HPLC pumps, and mulitpositional valves. To improve the robustness of the system, a rotary valve replaced two-way valves and the pumps were modified. 

Pump LKB 2150 HPLC Pump, ISCO 314 Detector ATTO AC-2220 (Lumlnomonltor I)... 

A microreactor was also applied to this reaction. The slit interdigital micromixer was purchased from IMM (Mainz, Germany). The width of the interdigital channels is 25 pm. HPLC pumps were used to feed the two reaction solutions. One is a mixture of Boc-AMP and 1.2 molar equivalents of r-BocaO. The other is a 50% aqueous KOH solution. The microreactor was immersed in a temperature controlled cooling bath at 15 °C. The product was quenched with an acid, and samples were taken for HPLC analysis. 

The high pressure continuous reactor consists of five Kenics type in-line static mixers, that were connected in series [3]. Each reactor unit has 27 Kenics elements and dimensions of 19 cm tube length and 3.3 mm inner diameter. Acetonylacetone and 1 % NaOH aqueous solution were pumped into the in-line static mixer reactor using two independent HPLC pumps. The in-line static mixer reactors were immersed in a constant temperature controlled oil bath at 200 °C so that the reaction mixture was heated to the reaction temperature. When the reaction was completed, the fluid was cooled down rapidly in a constant temperature cold bath at 0 °C. At the end of the cooling line, a backpressure regulator was placed to allow experiments to be run at 34 bar. 

P Ij The liquid volume flow to the micro reactor is controlled by an HPLC pump [38]. The gas flow was set by mass flow controllers. Temperature was monitored by resistance thermometers. 

The surface of the micro channels was anodically oxidized to create a pore structure and thereafter wet-chemically impregnated [61]. The liquid reaction solution was fed by an HPLC pump hydrogen was metered by a mass-flow controller. Pressure was kept constant... 

Another variation of the preceding method is to apply HPLC to fractionate the cleaned-up aliphatic-aromatic fraction from flash colurim separation of soluble organic matter as it is performed in the Chevron laboratory, for example, as described in Reference 2. A Waters HPLC system equipped with a preparative Whatman Partisil 10 silica column (9.4 X 500 mm), a HPLC pump, and two detectors for separation monitoring (a UV and refractive index detector) are used, giving three fractions of aliphatic hydrocarbons, mono-, di-, and triaromatics and polar compounds. The hrst two fractions are eluted with hexane, whereas polar compounds are eluted with... 

ShimadzuLC-lOAD VP HPLC Pumps (2) with 250-p.L high-pressure mixer and SCL-lOA VP pump controller... 

HPLC pump Waters 600E Multisolvent Dehvery System... 

A parallel screening system consisting of six equivalent tube reactors was constructed (10 nun diameter, 50 nun length). The reactor system operates in liquid downflow mode the liquid phase is fed into the reactor by an HPLC pump through... 

ESI-MS is the most successful method of coupling a condensed phase separation technique to a mass spectrometer. Because the input to ESI is a liquid, electrospray serves as an interface between the mass spectrometer and liquid chromatographic techniques, including SEC and CE (capillary electrophoresis). In LC-MS the flow-rate should lie in the range recommended for the HPLC pump and the mass spectrometer (typically 0.001 -l.OmLmin-1). Recent advances in (nano)electrospray technology include the development of the use of very low solvent flow-rates (30 to 1000nLmin-1) [130,131],... 

HPLC analysis for succinic acid, succinamic acid, succinamide, succinimide, N-methylsuccinimide, butyric acid, and propionic acid was performed with a Waters Model 515 HPLC pump equipped with a Waters Model 2410 Refractive Index Detector. Separations were performed with an Aminex HPX-87H 300mm column (Bio-Rad Laboratories, Hercules, CA) operated at 35°C, and using 0.005 M H2S04 elluent. 

Products were analyzed via Waters Model 515 HPLC Pump fitted with a Waters model 2410 refractive index detector. Separations was performed via an Aminex HP-87H 300mm column at 65°C using 0.005M H2SO4 as the mobile phase. Compounds calibrated for this work included xylitol, arabitol, erythritol, threitol, PG, EG, glycerol, lactate, 1-propanol, 2-propanol, ethanol, methanol, and the butanetriol isomers. Any compounds not visible by RID were not quantified in this work. 

The operating principles of three types of hplc pump are described, together with their advantages and limitations. Techniques for the production of solvent gradients and for the introduction of samples are considered. 

The instrumental setup for capillary HPLC-NMR coupling is shown in Figure 4.6. The capillary pump is connected via 50 pm capillaries between the capillary HPLC pump, the UV detector, and the NMR flow probe. 

NaCl or KC1 (Peng et al., 2003 Ballif et al., 2004 Beausoleil et al., 2004 Wilmarth et al., 2004 DeSouza et al., 2005 Vitali et al., 2005) may be used for the SCX fractionation, in spite of the incompatibility of these salts with mass spectrometers. When using KC1, for example, the sample must be desalted off-line (Ballif et al., 2004 Beausoleil et al., 2004), on the RP column before MS/MS acquisition (DeSouza et al., 2005 Vitali et al., 2005), with a vented column (Peng et al., 2003), or with a RP-trap (Vollmer et al., 2004 Wilmarth et al., 2004). The configuration with a RP-trap is shown in Fig. 11.1, and in this case, a flow splitter is used to reduce the flow rate from hundreds of microliters per minute to hundreds of nanoliters per minute. However, HPLC pumps of lower flow rate are now available and could eliminate the need for a flow splitter. 

Figure 8.5. Schematic view of continuous flow reaction setup for IL/scCC>2 systems (adapted from reference [81]). C compressor, CT cold trap, D dosimeter, DP depressuriser, F flowmeter, M mixer, MF metal filter, P HPLC pump, PT pressure transducer and thermocouple, R reactor, S styrene...

We developed a staggered parallel HPLC system with a CTC HTS PAL autosampler equipped with trio valves. The system consists of four (six if gradient is needed) independent HPLC pumps. Parallel analysis is achieved by an offset dual-stream system with a time delay that allows efficient staggering of MS acquisition times. 

---