LC Packings Dionex

Today nearly all of the major HPLC companies offer a pHPLC system or at least the possibility to modify a standard instrument to accept micro-bore columns. In our laboratory, we routinely use the pHPLC systems Ultimate from Dionex/LC Packing (Ligure 3.2), the Extreme Simple 4-D... 

FIGURE 3.2 (A) The Ultimate iHPLC system by Dionex/LC Packings, used in our laboratory forproteom-... 

Split systems simple (unregulated), regulated (HPllOO CapLC), and splitting at a high pressure level (Dionex/LC packings). 

This nib system connected to a capillary was then placed at the outlet of a nanoLC column for on-line analysis after a separation step.26 The column was monitored from a nanoLC setup (LC Packings-Dionex, The Netherlands). An amount of 1 pL of sample was injected (Famos injection system, LC Packings-Dionex) onto a commercial nanocolumn (PepMap, 75 pm i.d.) and eluted in gradient conditions at a flow-rate of lOOnLmin 1 (Utlimate micro pump and accurate stream splitter, LC Packings-Dionex) using solvent mixtures based on AcCN and deionized water (solvent A AcCN H20 5 95 solvent B AcCN-H20 95 5) acidified with 0.1% TFA. Ionization HV was 1.5kV, as typically used for a standard emitter tip. The sample used for this test is a commercial cyctochrome c digest at a concentration of 800 nM. The spray was seen to be stable for several hours (several nanoLC runs) as expected with a standard emitter tip. The analysis of the solution eluted from the column was possible and the same as for routine conditions. 

Rudolf-Virchow-Center for Experimental Biomedicine, Wurzburg, Germany LC-Packings—A Dionex Company, Amsterdam, The Netherlands... 

Ultimate Fully Integrated Capillary HPLC System from LC Packings/Dionex... 

There are a few commercially available monolithic columns on the market today, one of the first being the Chromolith from Merck, which uses a silica-based polymeric network for the high-speed separation of compounds of low to medium molecular weight at high flow rates with only low backpres-stues. More recently, LC Packings (a Dionex company) have released the Monolith , which is a polystyrene-divinylbenzene based monolith for the fast separation of proteins and peptides by micro LC. 

This results in co-crystaUization of matrix and sample and therefore higher sample concentration focused at the distinct hydrophilic anchor points [16]. One of the most commonly used matrices is a saturated solution of a-cyano-4-hydroxy-cinnamic acid in 97% acetone/3% water containing a small amoimt of TFA to support the ionization of the sample molecules in the MALDI source. The matrix is directed to the AnchorChip target and this is then dried. The sample fractionation after HPLC can be performed automatically using special sample fractionation systems (e.g., Probot, LC Packings Dionex). The target is introduced to a special desk and can be adjusted in the three XYZ planes so that the small nano-LC volume is placed directly onto the matrix. Using this set-up, fractions of volume less than 40 nL can be collected automatically. After collection, the individual fractions are recrystallized from 0.01% TFA, 30% acetone, and 60% ethanol in water and analyzed. 

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