Economical Preparative HPLC (Part 2 of 2)
Demands on a modern column for an efficient and economical preparative HPLC
To achieve a yield as high as possibly by overload, the column should have a high loadability. The highly selective and base deactivated NUCLEODUR® C18 HTec – especially developed for preparative applications – shows a considerably higher loading capacity in comparison with conventional phases. The “conventional phase” with a very good characteristic for analytical separations, used in the presented example for the comparison, already shows no baseline separation for a medium load.
In contrast NUCLEODUR® C18 HTec still features a clear separation and guarantees a high yield and purity.
Besides an adequate selectivity, which allows optimal separations, good base deactivation is important. If the analytical separation already shows tailing effects due to poor deactivation, then the preparative column prematurely reaches the load limits under overload conditions. This means that maximal yield and purity of the product cannot be achieved.
A long column lifetime is another factor influencing the economy of a preparative HPLC method. This is particularly important, if a maximum yield requires high sample throughput. Hence the column should feature a good lifetime, even for an application with extreme sample solvents, extreme pH values, increased temperatures, or with high flow rates, which an efficient operation sometimes may demand.
NUCLEODUR® C18 HTec is a reliable and durable RP phase with exceptional stability, which realizes highest lifetime, even under challenging conditions. Like every preparative phase from SORBTECH it is offered in VarioPrep columns with axially adjustable end fittings. If the adsorbent bed should settle after some time by strong chemical and mechanical stress on the column material, the dead volume can be compensated with a readjustment of the end fittings. The performance of the column will be completely reconstituted and its lifetime will be considerably extended.
Furthermore the lifetime can be extended with the use of guard columns. The new VarioPrep guard column system is a cost-efficient cartridges system, which features easy handling without impairment of the separation efficiency of the main column.
For an efficient and economical operation of a preparative HPLC method, column dimensions and phase parameters have to be adapted to individual requirements concerning purity, yield and throughput. A high loadability, optimal selectivity and good base deactivation of the phase enhance optimization of purity and yield. Moreover lifetime of the preparative column can be considerably extended with a high chemical and mechanical stability of the phase, with an adjustable column system and with the use of guard columns, thus reducing costs.
TLC separation of saffron ingredients with the new ALUGRAM® Xtra SIL G
Whenever a rapid and economical analysis from complex matrix is carried out, thin layer chromatography is the method of choice. Especially for the examination of food, where coloured or stained ingredients must be identified, a precise color recognition is important.
The TLC separation of saffron ingredients with the new ALUGRAM® Xtra SIL G with its optimized binder system, shows even with polar aqueous eluents the definite correlation of naphthol yellow S as main ingredient.
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VarioPrep Guard Columns – Perfect Protection of your Prep-Column
SORBTECH offers a new VarioPrep Guard Column system which provides perfect protection of your preparative main columns.
The cartridges are filled with specially fractionised NUCLEODUR® and NUCLEOSIL® silica, suitable for all SORBTECH columns as well as for various prep-columns from other manufactures.
The robust cartridge system offers:
easy, quick and simple handling and cartridge exchange
minimal invasive – no negative impact on separation efficiency of main column
lowest increase of back pressure
cost efficient cartridge system
VarioPrep Guard Columns are available in different dimensions (length/ID in mm) matching the individual needs of your preparative main column:
VP 10/8 for prep columns with 8 – 10 mm ID (requires holder REF 718251)
VP 20/16 for prep columns with 16 – 21 mm ID (requires holder REF 718250)
VP 15/32 for prep columns with ≥ 32 mm ID (requires holder REF 718253)