High-performance size exclusion detectors

Mori, S., Wada, A., Kaneuchi, F., Ikeda, A., Watanabe, M., and Mochizuki, K., Design of a highly sensitive infrared detector and application to a high-performance size exclusion chromatography for copolymer analysis, /. Chromatogr., 246, 215, 1982. 

High Performance Size Exclusion Chromatography (HPSEC) A Varian Model 5000 liquid chromatograph equipped with a variable wavelength UV detector, two columns in series (PL gel, 300 x7.5 mm, particle size 5/im, porosity of 50 and 500A), was used, THF being the eluent. 

High Performance Size Exclusion Chromatography. SEC was carried out on polystyrene-divinylbenzene gels with porosites ranging from 100 to 104A. The solvent, THF, had a flow rate of 1 ml/min. The detector was a differential refractometer. 

High-performance size exclusion chromatography (HPSEC) techniques with multiple online detectors (e.g., UV-, fluorescence-, or element-specific systems, Figure 10.6) enables a better understanding of quantitative and qualitative DOM properties... 

High Performance Size Exclusion Chromatography. The Hewlett-Packard 1090 liquid chromatograph was used with the HP 1040 diode array or HP 1037A refractive index (and HP 3392 integrator) detectors. A fifty A (5 mm, 300 x 7 mm) Polymer Laboratories PL gel (polystyrene-divinylbenzene copolymer gel) column was used and standards were as described in Chum et al. (13). Tetrahydrofuran solutions of oil and oil fractions were analyzed. 

Novolac molecular weights were measured in THF at 35°C by high pressure size exclusion chromatography using a Waters Model 510 pump (flow rate=1.0 ml/min), 401 differential viscometer detector and a set of Dupont PSM 60 silanized columns. A universal calibration curve was obtained with a kit of 10 narrow molecular weight distribution, linear polystyrene standards from Toya Soda Company. Data acquisition and analysis were performed on an AT T 6312 computer using ASYST Unical 3.02 software supplied with the Viscotek instrument. 

The determination of the molecular weight of nanoparticles is performed by gel permeation chromatography (GPC). The experimental setup consists of a high performance liquid chromatography system with a size exclusion column and a refractive index detector. The nanoparticles are usually freeze-dried and dissolved in tetrahydrofuran for analysis on the system. Poly(styrene) or poly(methylmethacrylate) standards are used to calibrate the column, to enable the determination of number average molecular weight (Mn), as in... 

High performance liquid chromatography (HPLC). All HPLC analyses were performed with a model HP1090 analytical HPLC equipped with a diode array detector (Hewlett Packard, Mountain, View, CA). A Protein PAK 3000 SW column (Waters, Bedford, MA) was used for each size exclusion experiment. The column was equilibrated with ten column volumes (100 ml) of elution buffer (2.0 M GuHCl, 50 mM Tris sulfate, 5 mM EDTA, pH 7.5) prior to operation. A sample volume of 25 gl was applied to the column and eluted at a flow rate of 1.0 ml/min to facilitate rapid separation. For equilibrium experiments, each sample was equilibrated for three to eight hours before column separation. 

Many components of SEC systems are well known and ubiquitous in an analytical lab. Size exclusion chromatography systems require at least an isoaatic pump, a high-pressure injection systan (manual or automated), one or more SEC colunm(s), one or more detector(s), and data evaluation units with software to acquire, calibrate, and analyze data. Other components, such as degassers or column compartments are often optional and depend on the particular application and on the lab environment and conditions. Although SEC and high-performance liquid chromatography (HPLC) seem to be very similar in instrumentation requirements, the theoretical background and separation mechanism of both techniques are entirely different. The major differences in the practice of SEC are outlined in Table 9.2. 

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