In addition to the standard products listed in this catalogue, TESSEK offers to prepare products for special applications, made according to your specifications.
The variety of combinations of particle size, porosity and functionality in different column types gives a wide range of possibilities to optimize your specific task.
TESSEK Separon SGX Spherical Silica-based Sorbents can be prepared with particle sizes 4, 5, 7, 10, 12, 15, 20, 30, 40, 60, 100 µm, the particle sizes of the raw material are usually in stock.
Apart from the standard SGX matrix, SGX 200, SGX 500 and SGX 1000 macroporous sorbents can be prepared in different particle sizes and modifications.
Hydroxyethyl Methacrylate-based Sorbents can be prepared with particle Sizes 7, 10, 12, 15, 20, 30, 40, 60, 100 µm, these particle sizes of the raw material are usually in stock.
The standard TESSEK Separon HEMA matrix, the TESSEK Separon HEMA-S (used for microparticulate HEMA 300- and HEMA 1000-based sorbents to improve mechanical strength) or the TESSEK Separon HEMA-BIO (hydrophilized matrix for high protein recovery in size exclusion, ion-exchange and affinity chromatography) can be selected with exclusion limits corresponding to 40, 100, 300, 1000 kDa (usually available in stock). Other porosities (HEMA 20 or HEMA 10000) can be prepared on request.
All standard modifications and many others can be prepared on the HEMA matrix to suit your individual needs.
A minimum order is usually required for custom-made products, the quantity depending on product type. Please contact our sales department.
Steel Column Spare Parts
The advanced design of the TESSEK steel columns allows their repeated
repacking without problems. A stainless steel sieve and a teflon
sealing ring are the only parts that need to be changed when repacking.
We provide these parts for both 8 and 4 mm ID columns and also
for the formerly produced 6 mm ID columns. The end-fitting sealing
rings must be replaced occasionally when end-fittings are changed.
Capillary Connecting Elements
Precisely machined low dead volume capillary-connecting elements are the necessary key to high-performance liquid chromatography. Any dead volumes in the injector to detector sample line will lead to losses in the column performance. TESSEK provides the necessary connecting elements for the coupling of our columns to virtually all types of chromatographs.
Two types of exchangeable coupling fittings are produced. The UNF 10-32 internal thread type is designed for use with bushings with US standard thread. The M5 internal thread type is designed for use with M5 bushings (metric thread). Please be careful not to change the two thread types. As they differ only slightly in dimensions, they will be damaged when tightened with force. The corresponding types can be tightened almost completely by hand. The head of UNF 10-32 coupling fitting is scored whereas the M5 is smooth.
We provide two types of compression ferrules for 1/16" or 1.5 mm OD capillaries: stainless steel for high pressure use and PTFE for medium and low pressure use. The PTFE ferrules are easily removable; however, their use is limited up to some 5 MPa.
The stainless steel bushings with a 1.6 mm ID are designed for use with the respective type of coupling fittings. When not in use, our polypropylene plugs for tight column closure can be used.
Additionally, we offer low dead volume unions for direct coupling
of capillaries and an union for direct coupling of TESSEK steel
columns (inserted instead the coupling union).
The art of stainless steel capillary cutting is quite difficult
without using special tools. TESSEK offers square-end precut,
stainless steel capillaries, 1.5 mm OD with 0.2 and 0.5 mm ID
in different lengths.
Blank Plastic Cartridges
The wide application of the SILICA-cart and HEMA-cart plastic
cartridges has proven the advantages of the patented design. We
offer the widest range of adsorption, reverse phase, ion exchange
and affinity support packings; however, special needs cannot always
be satisfied, in which case we can offer preassembled blank plastic
cartridges. These cartridges can easily be packed in laboratory
for immediate use. Dry or slurry packing (use vacuum for suction)
of 40 to 200 µm particles is a very simple task. All these parts
are provided with a standard syringe Luer cone.
For coarse filtering of highly polluted samples (fruit or vegetable juices, soil extracts, etc.), the filter is equipped with a glass fiber paper (Schleicher-Schuell No. 6), which retains particles over 3 µm effectively. For fine filtering of HPLC samples, the 0.45 µm pore nylon membrane (Schleicher-Schuell No. NL 17) is suitable for aqueous solutions, while the inert teflon membrane (Schleicher-Schuell No. TE 36) is necessary for organic solvents.
The microfilter is to be connected to a hypodermic syringe, where the sample is either applied in the filter cavity (max. 0.2 ml) or the whole filter is immersed into the filtered liquid. By withdrawal of the syringe piston, the sample is sucked through the filter into the syringe and can then be applied directly into the HPLC apparatus. With a 2 ml syringe, 1 ml the of sample can usually be filtered.
CAUTION: The filter is not intended for pressure application!