TSK-Gel, Toyopearl

Samples were fractionated by size on stainless steel columns packed with TSK-GEL ToyoPearl gel filtration medium, (Supelco Inc., Bellefonte, PA) in 50 mM NH4AC, pH 5.2. For HW-55 S (fractionation range for dextrans 1000-200,000 daltons) and HW-50 S (fractionation range for dextrans 500-20,000 daltons), the column was 10 x 500 mm and the flow rate was 1 ml/min. For HW-40 S (fractionation range for dextrans 100-7000 daltons),... 

SIZE EXCLUSION CHROMATOGRAPHY USING TSK-GEL COLUMNS AND TOYOPEARL RESINS... 

Like other GFC matrices, including TSK-GEL SW and TSK-GEL PW packings, and dextran and agarose gels, Toyopearl HW resins exhibit some ionic and hydrophobic interaction with samples. The hydrophobic properties of Toyopearl HW resins, however, can be utilized more effectively for improved protein purifications because, unlike numerous other GFC packing materials, Toyopearl HW resins can be used with high levels of organic solvent (38). 

The hydrophilic surface characteristics and the chemical nature of the polymer backbone in Toyopearl HW resins are the same as for packings in TSK-GEL PW HPLC columns. Consequently, Toyopearl HW packings are ideal scaleup resins for analytical separation methods developed with TSK-GEL HPLC columns. Eigure 4.44 shows a protein mixture first analyzed on TSK-GEL G3000 SWxl and TSK-GEL G3000 PWxl columns, then purified with the same mobile-phase conditions in a preparative Toyopearl HW-55 column. The elution profile and resolution remained similar from the analytical separation on the TSK-GEL G3000 PWxl column to the process-scale Toyopearl column. Scaleup from TSK-GEL PW columns can be direct and more predictable with Toyopearl HW resins. 

Two different sample preparation methods by size-exclusion and reverse-phase chromatography were proposed for analysis of PCs and PAs in wine. In the former, a volume of 5 mL of dealcoholized wine is passed through a Fractogel Toyopearl TSK gel HW-50 (F) (12 x 120 mm) column. The stationary phase is washed with 25 mL of water and the simple polyphenols are eluted with 50 mL of an ethanol/water/trifluo-roacetic acid 55 45 0.005 (v/v/v) solution. The polymeric fraction is recovered with 50mL of acetone/H20 60 40 (v/v). Figure 6.19 shows the LC/ESI-MS extracted ion chromatograms of dimers and trimers in a wine (Fulcrand et al., 1999). 

For determination of low concentrations of phosphate in natural waters, the selective preconcentration of phosphate may be required. An example of this was recently shown by Yuchi et al. who used a chelating column loaded with Zr for this purpose (TSK gel AF-chelate Toyopearl 650, 40-90 /rm, containing 30 /rmol/g iminodiacetic acid group). ... 

To collect the oxidation products, lAA-Asp was oxidized overnight in the mixture (30 ml) of 0.2 mM lAA-Asp, 0.4 [xM peroxidase, 0.1 mM H2O2 and 50 mM sodium acetate (pH 4.0) at room temperature. The oxidation products were applied to a Toyopearl HW 40 column (1.8x35 cm, Toyo Soda) and developed with a MeOH-0.1% HOAc (3 7, v/v) solution. Major peaks (60-95 ml) were collected and analyzed by HPLC (TSK GEL, ODS 120T, 7.8x300 mm, Toyo Soda) using a solvent of MeOH-0.05% HOAc (2 8, v/v), which produced four peaks (A, B, C and D) at Rvs of 40.8, 43.8, 48.7 and 57.2 ml, respectively. The products showed tautomer-like behaviors as follows A B and C D. Their UV-spectra were similar to that of OxIAA, but their hydrolysis with 2 M HCl at 100 C for 14 h yielded QCA and aspartic acid. Reasonable structures for the oxidation products would be... 

A number of techniques have been used for the preparative separation of flavonoids. These include HPLC, Diaion, Amberlite XAD-2 and XAD-7, and Fractogel TSK/Toyopearl HW-40 resins, gel filtration on Sephadex, and centrifugal partition chromatography (CPC). The choice of methods and strategies varies from research group to research group and depends often on the class of flavonoid studied. 

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