SU744322A1 - Apparatus for determining dosing volume of micrometering devices - Google Patents

Description

and the density of the dosed substance in the dosing volume of the microbatcher.

A disadvantage of the known device for measuring the dosage volumes of microdo: poros is the low accuracy of the determinations, which is the smaller, the smaller the measurable .1.1: the dosage volume of the micro dose is. the torus, and the range of definitions is not wide enough, limited by dosing volumes, not less than / and 5 μl.

The goal of the congregation is to increase the accuracy and broaden the range of definitions.

The supplied device is achieved by the fact that the known device for determining the dosing volumes of microdispensers containing the source of the dosing substance, the source of the a-carrier gas, storage tank, meter of the amount of the dosage substance in the storage tank and connected to the source of the dosing substance and the source of carrier gas is a microdosator with defined the dosing volume is equipped with a reference dosing unit, including a dosing unit with a dose of a known volume, the inlet of which is connected to the source of dosing exists, and output - with a source of carrier gas, and specify the number of node metered dose of substance n connected to the input of a dose doza1ora known volume, as well as to the input defined by the pipettor with a metering volume.

In addition, to achieve the goal, the storage tank is a thermo-adsorption concentrator including a cryo-thermostat driven to move within the cold and warm zones of the adsorbent column, the inlet of which is connected to the dispenser outlet with a dose of a known volume and to the microdosizer outlet with a defined dosage volume, and the output is to the amount meter (the amount of the substance to be dosed in the storage tank, moreover, , a chromatographic analyzer, and the unit for setting the amount of the substance to be dosed in a dose includes at least two pressure units with different setting ranges, each of which is connected to a corresponding absolute pressure gauge.

The drawing shows the scheme of the proposed device for determining the dosage volumes of micro-digesters.

The device contains a dosing source-stabilized source of the dosing substance // as a gas mixture, a flow-stabilized source of carrier gas 2, which is used as a low-adsorbing gas (helium), storage tank o, metering amount of the dosing substance in the storage tank 4, microdosing device 5 with dosing. volume 6, the UX value of which t) is determined to be determined, and the reference dosing unit 7, which includes the dispenser 8 with the dosing volume 9, which is known and equal to Vo, and the Jo task unit for the quantity of the dosing substance in the dose.

Inputs microdosing 5 and dispenser 8,

i.e. the channels through which the dosing substance flows are directly connected to the valves 11 and 12 of the node 10, and through the adjustable throttle 13 and the valves 14 and 15 respectively are connected to the source of the dosing substance 1. The dispenser 5 and the dispenser 8, t . E. Channels through which the carrier gas flows, through valves 16 and 17, respectively, are connected to the source of gas-1-usntel 2 and through valve 18 to storage tank 3.

The storage tank 5 is made in the form of a thermo-adsorption concentrator including a cryothermostat 19 with a drive 20 for moving within the cold

A | and warm "B ZOI column with adsorbent 21. The INTAIN entrance 1 is connected to the valve 18, and the output is connected to the PROFESSIONAL | Meter of the amount of the dosing substance in the storage tank 4, which is used as

chromatographic.: 1izator, including pa;: 22 column with detector 23 ;;, 1 outlet and analyzer of results of the analysis 24. On the line connecting the outputs of the column with the adsorbent 21 g, in the column 22, the valve is installed 25

The task node 10. The quantities of BfamecTBa dosed in proportion include at least two parallel channels. In the channel

A pressure gauge 26 and an absolute pressure gauge 27 are installed in the // valve, and a pressure gauge 28 and an absolute pressure gauge 29 are installed in a channel connected to valve 12. The pressure gauge 26 is used to set the low pressure

/ K2S

(0,., 1, out of the top J8 doses

I

ditch 5 and 5, and using the setpoint pressure 28 to set higher pressures

(D0.) with -I I

The operation of the proposed device includes three consecutive stages, and, surely; input into the thermo-adsorption concentrator using a microblower 5 series of samples of the dosed substance, taken at constant pressure, concentration of the amounts ;; real sample, its chromatographic analysis and calculation of the parameters of the separated peaks; input to the thermo-adsorption concentrator using a dispenser 8 of a series of reference samples of the dosed substance selected at different pressures, concentration, chromatographic analysis and calculation of the parameters of the separated peaks of each sample; comparison of the parameters of the divided total sample kicks entered by the microcircuits of doses of torus 5, with the parameters of the corresponding peaks of the samples entered by the dispenser 8, and the determination of the true value of the dosage volume of 6 microcoolers 5.

The device works as follows.

Preliminarily, by closing the valves 12 and 14 with an adjustable throttle 13, the required flow rate of the substance to be metered is set, and by the setting device 28, the pressure value PO in the input channels of the microdosing device 5, measured by measuring the absolute pressure 29.

In the initial state shown in the drawing, the dosing volumes 6 and 9 are located opposite the inlet channels of the dosing units 5 to 8, the valves 12, 14, 16, 18 and 25 are closed, and the remaining valves are open. The column with the adsorbent 21 is located in the cold zone “A of the cryothermostat 19. A flow of dosing substance under pressure PO flows through the dosing volume 6 of the microdosing device 5. which, via pressure setpoint 28, enters the discharge line. A stream of carrier gas with a constant flow flows through the outlet channels of the dispenser 5, the column with the adsorbent 21, the separation column 22 n the detector 23.

The dosing volume 6, filled with the dosing substance, is moved from the inlet to the outlet channels of the microdosing device 5. The sample gas discharged at the PO pressure q is washed away with the carrier gas flow «from the dosing volume 6 and fed to the cooled adsorbent of the olives 21, which absorbs the dosing substance. Dosing volume 5 is transferred to the inlet channels of the microbatcher 5, where it is refilled with the dosing substance, after which the dosing volume 6 is again transferred to the output channels of the microbatcher 5. The second sample 92 withdrawn by the microbatcher 5 enters the column 21 and is sorbed on the surface of the adsorbent. In the same way, 21 subsequent samples of the dosing substance are introduced into the column.

After a series of probes are supplied to column 21 of the cumulative, bone 3, the number of which is t, as well as the value of the pressure PO, is determined by an approximate estimate of the value of the dosing volume 6, the supply of samples to the microdosing device 5 is stopped. The amount of dosing substance Qo in the total sample, which will be accumulated on the adsorbent column 2 /, is:

Qo ,, (1)

(one

where K is the proportionality coefficient.

Then turn on the drive 20, which moves the column 21 from the cold “A to the warm” B zone of the cryo-thermostat 19. The drive 20 moves the column 21 to the warm zone after the start, starting from its entrance section. In the areas of the column 21, which were drunk in the warm zone "B, the adsorbent is heated, as a result of which the metered substance absorbed by the adsorbent is desorbed, and with a stream of carrier gas is transferred to the section of the column 21 that absorbs it during the cold zone "BUT. At the time of entry into the warm zone of the exit section 15 of the column 21, the injected samples will be collected. The bulk substances will be concentrated in one volume at the outlet of column 21 in the narrow narrow band, from where they are carried by a flow of carrier gas to an exponential LIZ in separating column 22 measuring the amount of dosing substance in storage tank 4, which was used as a chromatographic analyzer. The separated components of the dosed substance enter the detector 23, and their parameters are recorded by the recorder of the results of the analysis 24.

Entering the total sample for analysis can also be done by simultaneously heating the entire column 21, followed by purging it with carrier gas. To do this, after entering the samples into column 21, valves 18 and 25 are opened, interrupting the flow of the gas-carrier, the column 21 is transferred to warm

5 zone “B kr (iothermostat 19. After desorption of the dosed substance as a result of heating the adsorbent, valves 18 and 25 are closed again, and the carrier gas flow transfers the desorbed product to the separation

0 column 22,

After completion of the analysis of the samples of the dozn. of the substance to be injected, introduced by microdosing device 5 with a measured dose of 6, valves 12, 14 and 16 are removed, and column 21 is converted into

5 cold zone “A cryothermostat 19.

Next, the valves L / 5 and 17 are closed, the setting device 26 sets the pressure value P |, and the adjustable throttle J3 - the required flow rate of the dosing substance,

0 which flows through the dosing volume 9 of the dispenser 8, through the pre-pressure 26 and enters the discharge line. The flow of carrier gas with a constant flow flows through the outlet channels of the dispenser 8,

column with adsorbent 21, separation column 22 and detector 23.

The dosing volume 9 is transferred, filled with the dosing substance from the inlet to the outlet channels of the dosing unit 8. The separated pressure of the PI reference sample is flushed out of the dosing volume 9 and fed to the cooled adsorbent of the column 21, which absorbs the dosing substance. The dosage volume 9 is moved about the entrance canals of the dispenser 8, the actuator 20 is turned on, and the crank 2 / is moved from the cold A to the warm cryoremostat 19. The sample of the matter to be loosened. and when the microdosing device 5 is injected into the samples, it is concentrated in the form of a narrow band and fasting / drops into the separation column 22 for a separate analysis, after which the parameters of the peak components of the sample are recorded. Column 21 is transferred to the cold zone of the A Cryothermostat 19, and the cycle for analyzing the first of a series of reference samples introduced by the dispenser 8 ends.

The registered parameters of the peaks of the components of the first reference sample are compared with the parameters of the peaks obtained by analyzing the total sample entered by the microdosing device 5. If the values of the epich parameters turned out to be less than the values of the parameters of the corresponding peaks of the total sample introduced by the microdosing device 5, then at each subsequent cycle of analysis of the sample entered with the dosing unit 8, the pressure unit in the dosing volume P is increased by setting unit 26. Otherwise, the pressure value in the dosing volume 9 is reduced. In proportion to the pressure value in the dosing volume 5, the amount of the substance to be dosed in the identified sample, and consequently, the parameters of the peaks of the components of the dosed substance, changes.

After the end of each successive cycle of analysis of the reference sample introduced by the dosimeter 8, the parameters of the peak components of this sample are compared with; the parameters of the peaks obtained in the analysis of the total sample, introduced microdosing 5.

In one of the analysis cycles, at a certain value of pressure Рт in the reference sample selected for rotary dispenser 5, the recorded parameters of the components compound peaks of the substance to be dosed will be equal. Parameters of the corresponding camloniteite sum of the sample entered by the microdisator 5. The amount of the substance to be dosed Qm that was entered in this cycle for analysis, it is known:

.

(2)

The magnitude of the VC of the dosing volume 6 of the microbath 5 is determined from the following considerations. Equality of the parameters of the drills of the components of the dosed substance obtained during the alternation of the reference sample introduced by the dispenser S with a dosage volume of 9 of a known value of PP at a pressure of Pm, and the parameters of the same peaks obtained by analyzing p samples introduced by a microdosing device 5 with a dosage volume 6 of an unknown VK value at the pressure PO, means that the quantities of the dosing substance entered for analysis are equal to each other, i.e. Qm Qo- From this, taking into account expressions (1) and (2), the value of V of the dosing volume is 6 micropump 5 is equal to:

,

(3)

Claims (4)

one. etc, After determining the value of Vx, the south volume dosing volume 6 of the microbatcher 5 is disconnected from the device. In its place install another microdater, the dosing volume of which must be determined. Formula of the invention . A device for determining the dosing volumes of microdosers, comprising a source of the dosing substance, a source of carrier gas, a storage tank, a meter for the amount of the dosing substance in the storage tank and connected to the source of the dosing substance and The source of the carrier is a microdispenser with a defined dosage volume, oh, and chuyu so that, in order to increase the accuracy and broaden the range of definitions, it is equipped with a unit of the reference dose {| with a dose of the known o6rs.; a; the entrance of which is connected to the source; Dosage unit is available, and the output is with a gas carrier that carries the gas, and a task set for the number of doses metered in a dose connected to the input of the dispenser with a dose of a known volume, as well as to the input of the micromachine with a small volume, the volume of the volume. 2. A device for determining the pre-delivery volumes of microsize dozers according to claim I, distinguishes it with the fact that the storage tank is made in the form of a thermo-adsorption concentrator, including (driven by a thermo-irio thermostat for the limits of the cold and warm zones of the column with adsorbents, the input of which is connected to the outlet of the dispenser with a dose of a known volume and to the outlet of the microdispenser with a defined dosing volume mouth, and the output. dosing amount storage capacity / 3. A device for determining the dosing volumes of micro batchers for l. one-, . Distinguishing from the fact that as a measuring instrument for the amount of the substance to be dosed 3 storage tanks used:.: Atrographic analyzer. 4. A device for determining the dosing volumes of microbatchers according to claim 1, characterized in that the unit for setting the quantity of the substance to be dosed in a dose includes at least two pressure units with different task dialazes, each of which is connected to a corresponding absolute pressure gauge. Sources of information taken into account in the examination: 1. Sokoliy G. F. and others. Evaluation of methods for determining the working volume of chromatographic dosing cranes. - Scientific and technical. Sat sir “Automation and instrumentation, M., TsNIITEneftekhim., 1974, No. 11. 2. Bobylev A. V. Errors in the certification of pure gases by the chromatographic method. - “Measuring equipment, 1975, No. 6 (prototype).