Gilson fraction collector

Figure 11-5. Preparative LC/MS systems on the market consist of a binary HPLC system, a combined antosampler/fraction collector (footprint of a Gilson 215 inject/coUect hquid handler shown in the fignre), and a single qnadrnpole mass spectrometer.

It is very useful to have the mplc system linked to a fraction collector, -r.y kind of fraction collector will work, but we use a Gilson computer... 

When all the aforementioned system requirements were considered together at the design stage (late 1994. early 1995) it was decided that the manufacturer whose range of products could most easily provide all the necessary hardware was Gilson. Therefore all the method and system development was carried out on a modular Gilson preparative instrument based around the 23. XL autosampler/fraction collector, which we termed as an autoprep system and which is shown in Fig. 8.1. 

Preparative HPLC was performed on a Gilson instrument equipped with two pumps (305/303 model), a magnetic mixer (811C model, 23 ml), an injection loop (5 ml), a UV detector (119 model, variable length), and a fraction collector (202 model) with 10 ml glass tubes. 

For the laboratory prototype a Gilson fraction collector was used. The whole setup as depicted was named MICROTAUROS (Fig. 15.14) (microreactor for automated reaction optimisation) and worked fairly well with only a few drawbacks. The length of the tube necessary for reaching every position on the fraction collector rack precluded very short reaction times. Higher pump rates would compromise the advantage of a laboratory system with the rather small amoimts of materials and small syringes. A much more severe drawback is the fact that a three-way solenoid valve had to be used. In the equilibrium phase the material stream is switched to waste and only diverted for collection of analytical samples. 

Countless are the circumstances that cause a protein purification to fail the column draws air, the pump tube is worn through, the wrong buffer was used, inlet or outlet tubes are leaking, the column is blocked, the dialysis tube has a hole, the cooling cell fails, and fraction collectors have a tendency to quit just when the precious protein eludes in the last purification step. Lucky is he who owns a pump, has a reliable fraction collector (e.g., from Gilson) and good columns (e.g., from Pharmacia), and does not have to lend these tools to colleagues. 

Countercurrent Chromatography Procedure. The entire column (pair of coiled multilayer columns connected in series) was filled with the stationary phase. The apparatus was then rotated counterclockwise at 600 rpm in planetary motion while the mobile phase was pumped into the inlet of the column at a flow-rate of 2.2 mL/min (head to tail elution mode). Maximum pressure at the outlet of the pump measured 80 psi. After a 1-hour equilibration period, the sample was loaded into the Rheodyne injector loop and injected. Effluent from the outlet of the column was continuously monitored with a Shimadzu UVD-114 detector at 312 nm and fractions collected with a Gilson FC-lOO fraction collector to obtain approximately 8.8 mL of eluant in each tube (during a 4-min interval). Retention of the stationary phase was estimated to be 930 mL (74%) by measuring the volume of stationary phase eluted from the column before the effluent changed to mobile phase (330 mL) and subtracting this volume from the total column capacity of 1260 mL. 

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