US3542093A

US3542093A - Fractional collector

Info

Publication number: US3542093A
Application number: US663441A
Authority: US
Inventors: Wolfgang Pollmann
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-08-25
Filing date: 1967-08-25
Publication date: 1970-11-24
Anticipated expiration: 1987-11-24

Description

6 r rte StatesPatent. H 13,542,093

[72] lnventor Wolfgang Pollrnann [56] R f i Cited 7 Goldbergstrasse, 3554 Marburg-Cappel, UNITED STATES PATENTS [21] A l N 2 32? 3,209,795 10/1965 Page 141/130 3 239 312 3/1966 Bell m1 23/2s9x [22] Filed 3 268 117 8/1966 L k 141/131x [45] Patented 24,1970 en ey e a. FOREIGN PATENTS 1,374,357 8/1964 France 141/130 Primary Ex'aminer- Laverne D. Geiger Assistant Examiner- Edward J. Earls Attorney-Watson, Cole, Grindle & Watson [54] FRACTION/1L COLLECTOR 7 Claims 6 Drawing Figs ABSTRACT: Apparatus for the fractional collection of an ex- [52] U.S. Cl. 141/284, tracted material to be poured into a plurality of vessels sup- 23/253, 141/130 ported in a stationary rack. The material extract is fed into the [51] Int. Cl. G01n 1/10 vessels from a movable carriage from a feed member through [50] Field 01' Search 23/253, the intermediary of a distributor plate which is supported over said vessels by said rack.

Patented Nov. 24, 1970 3,542,093

Sheet 1 of4 Inventor W Pa 2317757772 Inventor W. Pow-271517172 Z /Im; 4

Patented Nov. 24, 1970 Sheet Patented Nov. 24, 1970 Sheet Inventor B W pozzmann FRACTIONAL COLLECTOR The invention relates to an instrument for fractionated collection of a liquid (eluate), comprising a multiplicity of catching containers held in a bearer, e.g. test tubes, into which the liquid. is dripped consecutively from a nozzle.

Such instruments are required for liquid chromatography. To this end, the liquid-whose ingredients are to be separated from each other, travels downwards in a column within a substance of great surface (silica gel). Depending on the capacity of adhesion of the substances present in the solution with the charge, the substances 'will drip out of the column sooner or later. The liquid should now be collected in different vessels by meansof a fraction or fractional collector, so that it may be determined precisely thereafter, which portions of the liquid had left the column at aparticular time.

Known fractionalcoll ectors mostly comprise a displaceable bearer for the catching vessels(test tubes as a rule); The displac'eable bearer generally has the shape of a merry-go-roun d, on which the test tubes are positioned along several concentric part circles. The nozzle for delivery of the liquid is stationarily arranged as a rule; the merry-go-round is displaced in such manner that the catching vessels which are to be filled are positioned consecutively beneath the outflow orifice. Switching along occurs in steps. Control of the stepped displacement is carried out by means of electrical systems, relays being employed for this purpose, whose pulses are amplified by means of electronic amplifiers and valorised for switching a motorised driving'system which moves the merry-go-round along in steps. v l

a 1 This so-called extinction curve must also be recorded as a ruleduring fractional collection of a liquid. This is performed by means of a scribing appliance which records the colour (density value) which had been measured by means of a special instrument, on a strip of paper. So that the connection interruptions of laboratory experiments, since repairs are difficult and as a rule cannot be performed except by the suppliers or other specialised undertakings. An electrical-electronic system comprising switching relays is too sensitive as a rule moreover, to be able to work reliably inside a cooling cabinet. Cooling of the material collected is more difficult moreover, since the moving bearers cannot be fitted without difficulty within a container filled with coolant, since their entraining mechanism would be damaged thereby, and because displacement is considerably impeded if not prevented by the fluid or even a viscous mixture. Fractional collectors incor porating stepped drive of a merry-go-round moreover require a two-colour recorder that is a recorder comprising an entry pulse emitter for recording of the extinction curve, which entails considerable extra expenses for an instrument of this nature.

According to the invention, an instrument of this nature cited initially is now referred to in such manner that the successive filling is possible without application of costly electrical switching systems. The device according to the invention should moreover allow of direct comparison between the exlation over the apertures of the catching vessels. The driving device may comprise an electric motor preceding a reduction gear and a lead screw which engages in a tapped hole in the nozzle bearer. An instrument of this .kind can be produced cheaply, since displacement of the test tube holder is unnecessary. These tubes can be situated in a cheaply manufactured stationary bearer of holder, whereas the continual displacement of the nozzle is equally easy to provide structurally.

In an advantageous development of the inventive device, it is arranged so that a distributor plate is situated above the catching vessels and having catching recesses or depressions for the eluate and separated from each other by thin edges or webs, one catching recess being incorporated for each catching vessel and in communication with the same. With such an arrangement of the instrument, it is reliably assured that no liquid is lost between the different catching vessels.

An example of the invention is illustrated in the drawings. Further details of the invention emerge from this illustration, from the following description of the illustration and from the subsidiary claims.

In the drawings;

FIG. 1 is a perspective view of a fractional collector accord ing to the invention,

' FIG. 2 is a plan view of the fractional collector,

FIG. 3 is a front elevation of the fractional collector,

FIGJ4 is a sideview of the collector,

FIG. 5 is a longitudinal section taken on the line V-V of FIG.- 4 in the direction of the arrows, and

FIG. 6 is across section taken on the line VI-Vl of FIG. 3 in the directionof the arrows.

tinction curve and the contents of the test tube, without 7 requiring preliminary correlation to be established between recorded entries and test tubes. Rapid and direct evaluation of the fractions should moreover be rendered possible even in the absence of a recording system. I

The inventive instrument for fractional collection is charac: terized in that the bearer is stationary andthe nozzle is equipped with a continually operated driving device for trans- The principal parts of the fractional collector are a liquidproof container or tank 1, in which is housed a holder or rack 2 (see FIG. 5) for the catching vessels, a distributor plate 3 which simultaneously acts as a cover for the tank 1, a nozzle holder or carriage 4 which is movable along the distributor plate 3, and a driving device 5 by means of which a spindle 6 is driven slowly, which spindle moves the carriage 4. These components of the collector are described in greater detail hereinafter.

It is plain from FIGS. 5 and 6 that the vertical sides of the tank are double and consist of an inner side 1a and an outer side lb. A substance 7 providing satisfactory thermal insulation for example, glass wool, is situated in the cavity between the sides la and 1b. The bottom 8 of the tank does not contain any insulating material since heat radiation from below is not slight. Feet 9 are secured to the base and two connecters 1t) and 11 are arranged on the front longitudinal side of the tank,

a which allow of inflow and outflow of a coolant, as for example,

cooling brine. In order to force the cooling brine to traverse the entire space within the tank, a deflector plate 12 is pro,- vided between the inflow 10 and outflow 11, and which prevents the coolant from flowing direct to the outflow opening 11 along the front side.

Within the internal space of the tank 1 is provided the rack- 15, for reception of the catching vessels 13. This rack has two sidewalls 14a and 14b, a base 15, an intermediate wall 16 and an upper wall 17 The base 15 is at a certain distance from the base 8 of the tank. This distance is maintained by the lower extremities of the sidewalls 14a and 14b which act as feet. In the partition 16 and the upper panel 17

holes

18 and 19 are provided in alinement with each other, which have a slightly greater diameter than the test tubes 13. It is apparent from FIG. 6 that a total of six test tubes 13 may be stowed across the width of the rack 2, and the test tubes are in staggered positions, that is to say as apparent from the broken-line circles 20 in the FIG 2. Although the broken-line circles 20 do not indicate the test tubes, they are situated immediately thereabove, which will be explained. Since a total of seventeen transverse rows of staggered holes is present along the length .of the

panels

16 and 17, there is room in the rack for a total of 6 X 17 102 test tubes 13. Concerning the structure of the rack, it will be noted moreover that the side 14a and 14b form one piece with the upper panel 17. Carrying handles 21a and 21b, FIG. 5, are secured at the curvatures through which the panel 17 merges with the sides 14a and 14b. The rack 2 can be lifted out of the tank 1 as a unit, and it is preferably made of plastic.

The distributor plate 3 is fastened to the tank 1 by means of fittings 22 and on theses fittings there is provided a hinge 22 which renders it possible to tilt the plate 3 upwards together with its superstructure. The plate 3 is made of a chemically impervious material, as Perspex. On the upper side of the distributor plate 3 are provided as many grooves or troughs 23 as there is room for test tubes in the rack 2. The arrangement of the grooves 23 is apparent from the plan view according to FIG. 2. A group of six grooves consists of two

short troughs

23a and 23a, two troughs 23b and 23'b of medium length, and two grooves or troughs 23c and 23'c, of greater length. Each of the troughs is coordinated with a perforation 30 of the plate 3 (see FIG. 6). These perforations open out in the underside of the plate 3, above the test tubes 13 in each case. It is apparent from FIG. 6, that the opening of each bore 30 is encircled by an annular groove 31. These annular grooves 31 are so provided that the opening 32 of the bore is provided has a sharp edge. The broken-line circles 20 according to FIG. 2 indicate the outline of the annular groove 32. It is apparent from FIGs'S, that the wall between the individual troughs has a relatively sharp annular rim 33. Vertical crosspanels 34a and 34b and equally vertical longitudinal panels 35:: and 35b, are fastened to the distributor plate 3, and these panels consist of a transparent material, as Perspex. On the rear longitudinal panel 35a are fastened fittings 36 which have a hinging point 37 at the top, by means of which a fitting part 38 is hingedly secured. This fitting part is joined to a lid 39 equally made of transparent material. It is apparent, FIG. 6 in particular, that the lid 39 may be raised whilst pivoting about the hinge pin 37. The

panels

34a, 34b, 35a and 35b and the lid 39 conjointly enclose a hollow space 40 within which the carriage 4 is displaceable.

Two

guide rods

41a and 41b are provided in the space 40 for guiding the carriage 4 and as apparent in FIG. 2, these rods are 34m the cross panels 340 and 34b. The carriage has the cross section apparent from FIG. 6, from which it is noted that it comprises a basic unit 42 traversed by the

rods

41a and 41b. On this base unit is situated a cover plate 43, which is secured by means of knurled 'nuts 44a and 44b, which are screwed on threaded studs 45a and 45b, anchored in the base plate 42. Into the cover plate 43 is screwed a connecter stub 46 which has the curved shape apparent from FIGS. 3. A thin tube of hose 48 is connected to this stub by means of a coupling nut 47 and a flexible flap 49 of triangular shape is fastened to the cover plate beneath the connecter stub. To make room for this flap, a perforation 50 is provided in the base unit 42. From FIG. 2 it is apparent that a part 51 is laterally screwed on the carriage unit.

As already stated initially, a lead screw 6 driven by the driving device is employed for driving the carriage. The lead screw 6 engages in the tapped bore 52. Only the case and a switch 53 (see FIG. 4) are visible as to the driving device 5. Within the case is situated an electric motor supplied by a lead 54 and a reduction gear by means of which the speed of revolution of the motor may be geared down in different ratios, so that the spindle 6 can run at an extremely low speed of revolution. The switch 53, FIG. 4 is coordinated with a scale 55 marked with FIGS. from 0.05 to 50. A warning lamp 56 which lights when the instrument is in operation, is also provided on the case. On the case of the driving device is located a sleeve-shaped extension 57 which may be threaded over a cylindrical extension screwed fast on the transverse panel 34a. By so threading the same over, the driving device is automatically coupled to the extremity of the spindle 6 projecting out of the transversal panel 34a.

The instrument according to the invention operates as follows. The tube 48 is connected to the column from which the liquid drips. The spindle is driven by the driving device 5 at such speed of revolution that the carriage 4 moves at a desired speed and this speed is set by means of the selector switch 53. If this switch is set to the FIG. 0.05 for example, the spindle runs at such speed that 0.05 fractions are produced per hour. This means that the carriage 4 is moved forward through a single trough interval only, within 20 hours. If the switch is set to 50, the carriage passes 50 troughs in an hour. As apparent from FIG. 6, the flap 49 protrudes slightly into the troughs 23 and during the displacement of the carriage, the tip of the flap comes into contact with the side of the trough and the flap is increasingly bent. At a quite definite instant, the flap suddenly passes over the side of the trough and engages in the next trough. This prevents the liquid from dripping simultaneously into two troughs at the point of transition form one trough to another.

When the appropriate number of fractions has been produced, the distributor plate 3 is folded upwards and the rack 2 is lifted out of the tank 1 together with the catching vessels l3 situated therein. The test tubes 13 may now easily be withdrawn for further examination of the fractions.

During the dripping of the liquid beneath the distributor plate, the sharp rim 32 encircling each bore orifice 31, prevents the drops from adhering to the underside of the plate and from seeping along the same. An imprint of the underside of the plate may moreover be produced, that is on a strip of filter paper. The sharp edges of the outflow holes lying in or projecting slightly beyond the plane of the underside of the plate, concomitantly ensure that clear impressions are formed. By spraying the underside with appropriate chemicals, that is by dipping the same in such chemicals, it may be determined immediately by means of a simple template of transparent paper, whether and in which catching vessel the substances of specific type are situated.

If the investigation requires the catching vessels to be kept within a cold environment, a cooling brine is fed in through the connecter stub 10, which swirls around the test tubes and emerges again through the outflow connecter 11. A scribing recorder may be connected to the instrument. In this case, the paper feed or the recorder is coupled to the feed of the carriage 4.

Iclaim:

1. Apparatus for the fractional collection of a fluid (eluate) comprising a stationary rack receiving a plurality of vessels therein, each vessel being provided with a fluid receiving opening, a carriage movable over the top of the vessels and having a connecter stub and a feed member for the fluid, a driving device for the carriage to move the feed member over the vessels and a distributor plate arranged over the vessels and having grooves therein with sharp edges to direct the fluid into the vessels with each groove having an outlet opening to communicate with one of the vessels, said feed member guiding the fluid into the grooves.

2. Instrument according to claim 1, characterized in that the driving device comprises an electric motor, a reduction gear driven by said motor and a lead screw driven by the gear, which screw engages in a tapped hole of the carriage.

3. Instrument according to claim 1, characterized in that the lower extremity of each outlet opening has a sharp edge, the plane of the edge being flush with the underside of the distributor plate.

4. Instrument according to claim 1, characterized in that the openings of the vessels are arranged in a staggered pattern as seen at a right angle to the direction of displacement of the carriage, and the outlet openings for said grooves in said plate being formed in a staggered pattern identical with the pattern of said openings.

5. Instrument according to claim 1, characterized in that the grooves slope towards their outlet openings.

6. Instrument according to claim 1, characterized in that a quick-action device is arranged on the feed member to communicate said feed member with the grooves in the distributor plate and which device causes sudden transfer of the fluid filling operation between adjacent grooves.

filling operation between adjacent grooves, the quick-action device is formed as a flexible member which projects into the grooves.