SU769431A2 - Preparative liquid chromatograph - Google Patents

Description

The invention relates to liquid chromatography, and more specifically, to high pressure preparative liquid chromatography.

According to the main author. St. N ° 476503 is known preparative liquid chromatograph, soda. the elution system, the detection system, the NI and the system for collecting fractions from detector signals, including traps connected to the detector sensor output via switching valves, controlled by the detector signals and made in the 3 cases of the detector flow cell of the detection system in such a way that the channel volume from the output is flow cells to the switching element of the corresponding valve, less than the volume of the flow cell of the detection system. Switching selection valves for fractions of this chromatograph are made in a membrane valve with pneumatic valves, and when selecting a fraction, the control cavity of the corresponding valve is connected to the atmosphere, allowing the eluate to pass through this valve. This chromatograph works well at relatively low pressures. With a higher pressure, for example, a photon pressure of 100–200 ms / cm, gases dissolved in the eluent are released in the detector cell and, as a result, there will be a constant background noise or sudden bursts at the detector output. The constant background noise does not allow the selection of peaks (fractions) at the optimum level — the selection level has to be increased and thus the efficiency of the instrument decreases, since a significant amount of each divided fraction is sent to a reset. In addition, when passing through the detector cells, a case of 0 gas bubbles at the detector output: og; zl .: gots cutting bursts and the automatic collection mode of the fraction is disrupted.

The aim of the invention is to improve reliability and productivity.

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The goal is achieved by the fact that a membrane pneumatic valve installed at the outlet of the column is connected to the atmosphere through a regulating choke.

On f: ng. 1 shows a preparative liquid chromatograph circuit; in fig. 2- flow measuring cells together with selection valves (a - detector for dielectric constant, b - photoglastic detector); in fig. 3 - selection valves of the fraction collection system (section /1-.4 of Fig. 2); in fig. 4 - clans of the selection of systems for collecting fractions (section bb of Fig. 2); in fig. 5 - chromatograms (a- without the use of the invention, b - with

30 use).

. Preparative liquid x-romatograph Contains an elution system - pump V for feeding eluent, dispenser 2 "divided by CivrecH, section, effective) column 3, detection system, sensor 4 and measurement system and CII 5 register, fraction collection system according to c1d, nala: m detector - command block in the air; pneumatic valves, and 7 and 5 .and traps 9.

The robust cell of the sensor 4 burned by the application of the dielectric permittivity detector is formed, for example, by heart 10 and KopinvcoM 11 and has a slot 12. The switching valves of sensor 4 are channels 13 and 14 blocked by membranes / 5. The membrane is obtained by pressing a flexible film against the casing // of the gasket 16 with notches 17. Channels 18 are used to supply command signals (gas) to the wall 15, the control cavities of the membrane clamps are connected to the atmosphere via a choke 19 The flow cell of sensor 4, when using a photometric detector, is formed by camera 20 between windows 21. Commutruck X sensor valves 4 are channels 13 and 14, which are blocked by diaphragms 15. The membrane is received by pressing an elastic film to frame G1 using Lrockl 16 for cut-outs 17. Channels 18 serve to load command signals (gas) onto the / i5 membranes. The control cavities of the membrane valves are connected to the atmosphere through the choke 19.

Preparative liquid chromatograph works as follows. The eluent stream, along with the separated fractions, is directed from colony 3 to detector sensor 4. Depending on the difference in physical properties between the eluent eluate, the output signal of the detector varies. This change is recorded by the measuring system 5. When a certain fraascin is detected in sensor 4, system 5 supplies the unit with a command to turn off one of the pneumatic valves, for example valve 8. The command gas pressure is removed to a level maintained by the throttle 19. All other membranes 15 are under pressure command gas, L1rbyvyshimuyu for a certain amount nalor, / supported

drosel 19, and the passage of the eluate in the remaining traps is closed. Sugar, therefore, can only escape from the measuring flow cell under a defined pressure necessary to prevent the gases dissolved in the zyluate from being released.

When selecting completely separated fractions, it is advisable to set the level of selection of the automatic mode of operation of the chromatograph as close as possible to the zero line. Without the application of this invention, this is difficult due to the high level of interference caused by the gases that are liberated from the eluate in the detector cell. In addition, bursts caused by random gas bubbles and exceeding the level of fraction selection violate the automatic mode of operation of the chromatograph.

When applying the invention, the efficiency of the selection of each peak (each fraction) is increased by a magnitude equal to

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In addition, it is ensured that the installed automatic operation is maintained due to the absence of: bursts, (caused by air bubbles. This increases the reliability of the chromatograph and increases the K-PD.

As a detector in the proposed x) rotograph, as well as lamely-dielectric and photometric permeability detectors, other types of detectors - electrical conductivity, fluorescence: etc., can be used.

Claims (1)

1. USSR author's certificate No. 476503, G 01 N 31SCH 1975 (prototype). Compressed eZoZuh In the air --Cm sixteen . 6 13 T s chTIPK 13 JO} h. Phi Z MPt: s. Liki coomg fncSyfou u ypaffiiHu Bcn / iecK, St / afaHHbiu bubble gas