1. How do I access Tosoh’s HPLC Application Database?
The Tosoh Bioscience LLC web site contains a direct link to the Tosoh Corporation HPLC database on our main navigation. This database contains many application examples that demonstrate the performance of Tosoh’s chromatographic products. The sources of these applications include published articles in scientific journals as well as technical papers and presentations generated by Tosoh scientists.
Search the Application Database.
2. What is the cause of negative peaks?
A negative peak is a peak that dips below an established flat baseline. Negative peaks arise when the refractive index or UV absorbance of the solute is less than that of the mobile phase. When using an RI detector, simply reversing the polarity of the recording device will make the peak show up as a positive signal. The same ‘trick’ is applicable when using a UV detector, although this is rarely needed since most mobile phases have much lower UV absorptivity at the wavelength where the solutes have significant absorption.
Negative peaks are most often seen at the beginning of the chromatogram, where differences in the composition of the sample solvent and the mobile phase may give rise to an unretained solvent peak that first shows a positive deflection, but then goes negative before returning to the baseline. Since measurements are best performed when peaks elute after two or three column volumes have passed through the column, i.e., k=1 or 2, such ‘solvent’ peaks are usually ignored.
3. What endfitting do I use with my particular TSKgel® column?
Please visit the HPLC Columns - Replacement Parts page, which will provide a description of the available fittings, including the size of the frit in the fitting and the applicable endfitting to be used with your TSKgel® column. Question #10 includes additional information on fittings and connectors.
4. What does TSKgel® stand for?
The original name of Tosoh Corporation, the parent company of Tosoh Bioscience, was Toyo Soda Manufacturing Co., Ltd. TSK is short for Toyo Soda Kogyo (manufacturing in Japanese). The word “gel” is the generic term for the resin used in our columns.
Tosoh owns a registered trademark for TSKgel®. The mark TSKgel® is used when we refer to a particular column, such as in a product description, and when referring to a product line or to multiple columns of the same type. TSKgel is also used as the brand name for the line of bulk resins in the 20 and 30 micron particle size range, which are used to pack high efficiency preparative columns in intermediate-scale manufacturing of biopharmaceutical drugs.
5. What is the significance of “-5PW” when referring to TSKgel® columns?
Polymeric based Size Exclusion Columns supplied by Tosoh Bioscience start with a base support material. One of these supports is methacrylate derivative with a pore size of 100 nm. This is the same resin used in the TSKgel® G5000PWXL columns. So when this resin is functionalized with a ligand such as sulfo propyl the product is called SP (for sulfo propyl) -5PW (for the G5000PWXL support matrix).
6. What kind of fittings and connectors will I need in order to use TSKgel® HPLC columns?
The choice of fittings is dictated by the type of housing that contains the packing material. Most stainless steel and PEEK columns employ endfittings with 10-32 female inlet threads. Standard 1/16" OD stainless steel or PEEK tubing is used to connect the column to the guard column (or injector) and the detector. We recommend the use of “fingertight” style PEEK fittings with 1/16" OD PEEK tubing throughout your chromatography circuit.
Several of our polymer-based packings are also available in glass column format. These columns employ endfittings with ¼-28 female inlet threads. ¼-28 fittings are typically used with 1/16” OD Teflon tubing for low to medium pressure applications.
7. What quality control procedures are used by Tosoh Bioscience to assure column performance?
Tosoh Bioscience strives to attain the highest possible consistency and quality of performance for its columns and resins. The support resin, e,g, silica, is tested thoroughly for both physical and chemical characteristics. Once a ligand is attached to the base matrix the material is tested again according to stringent QC methods. Finally, after the resin is packed the individual column is tested with an analyte. This analysis is sent with the column on a sheet called “Inspection Data”. EVERY TSKgel® COLUMN IS TESTED INDIVIDUALLY BEFORE RELEASE FOR SALE AND THE INSPECTION DATA SHEET IS PROVIDED FOR FUTURE REFERENCE.
8. Please explain the lot numbering system used for TSKgel® columns.
The column numbering system consists of 2 parts:
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the column serial number which is unique to that specific column.
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the lot number which is the alphanumeric sequence after the dash in the column number. For example:
H4321-05H Serial No: H4321 Lot No: 05H
The lot number refers to a production run of packing materials. Occasionally resin lots have a small amount of material remaining in which case 2 or more of these small amounts are combined to make a “mixed” lot designated by the letter “M”, e.g. -10HM.