SU1509727A1 - Apparatus for recording chromatograms - Google Patents

Abstract

The invention relates to gas and liquid chromatography. The aim of the invention is to accelerate the registration process and reduce the complexity of processing the results. A device for recording chromatograms contains a potentiometer block, a detector, a detector signal amplifier, a limiting amplifier, two pulse formers, a pulse counter, a memory device, a differentiator, a pulse, a shift register, an analog switch, an analog-digital multiplier-dividing device, a recorder, a key, comparator, alarm device. 2 Il.

Description

The invention relates to gas and liquid chromatography and can be used for rapid chromatographic analysis of the composition of mixtures, for example, with norm control.

The purpose of the invention is to accelerate and reduce the complexity of processing the results.

FIG. 1 is a block diagram of a device for recording chromatograms; FIG. figure 2 - time diagrams of signals ..

The device comprises a potentiometer unit 1, a detector 2 connected in series, a detector signal amplifier 3, and a limiter amplifier. 4, the first driver 5 pulses, the counter 6 pulses, memory

device (memory) 7, and the outputs of the counter 6 pulses are connected to the address bus (ASH) memory 7, the differentiator 8, the second pulse shaper 9. ,, shift register 10, analog switch T 1, -analog-digital multiplying-dividing device (ADMDU ) 12, the recorder 13, the key 14, and the output of the amplifier 3 of the detector signal is connected to the information output I of the analog-digital multiplier-dividing device 12, as well as through a series-connected key 14 to the input of the differentiator 8, the output of the differentiator 8 is connected to the input of the second form Ate 9 pulses, the output of the second shaper 9 pulses - with a register input 10

SP

about go

shift, as well as with the third control input of the analog-digital multiplying-dividing device 12, the outputs of the shift register 10 are connected to the control inputs I of the analog switch I1, the outputs of the potentiometer unit 1 - with the information inputs II of the analog switch 1 1, the output .. analog switch 11 - with the second Q. Information input of the analog-digital multiplying-dividing device 12, analog output of the analog-digital multiplying-dividing device 12 - with the input of the recorder 15, 13, and also with the input of the comparator 15, the output of comparator 15 — with the input of the detector 16; the output and input buses of the analog-digital multiplier-separator 12 — respectively, with the input and output buses of the memory 7. In the signal timing diagram, the following symbols are taken: and the signal of the detector 2; B - the signal generated by the limiting amplifier 4; 6 - pulse at the output of the first driver 5 pulses, generated by the front, front of the signal of the amplifier - limiter 4; g - differential signal from the output of the differentiator 8; o is the pulse at the output of the second imaging device 9 pulses, which appears at the moment when the chromatographic peak reaches its maximum.

The device works as follows.

In the calibration mode the operator at the outputs of the block. 1 potentiometer sets the voltage U o; proportional to the concentrations of the components C of the calibration mixture:

-15097274

its input and having a profile of a chromatographic peak (Fig. 2a), a rectangular signal (Fig. 26), the leading edge of which causes the appearance of a pulse (Fig. 2c) at the output of the first pulse generator 5. These pulses are fed to the counting input of the counter 6 pulses.

Thus, the code at the outputs of counter 6 becomes equal at the moment when the output of the i-th chromatographic peak begins. This code goes to the address bus of the charger 7. At the same time, the signal from the output of amplifier 3 is fed to the input of differentiator 8. The differentiated signal (Fig. 2d) is fed to the second driver 9 of pulses, at the output of which a pulse appears (Fig. 2e) at the moment of output the top of the chromatographic peak. This pulse arrives at the control input of the shift register 10. Upon receipt of the 1st pulse, the i-line of the output bus of the shift register is excited, which is equivalent to the excitation of the i-th line of the control bus 1 of the analog switch 11. At the same time, the i-line of the information bus 2 of the analog switch 11 is connected to its output.

Since on the i-th line of the input bus switch 11 acts for the sake of

thirty

If UQJ 5 is determined by expression (1), then this voltage is applied to the information input 11 of the analog-digital multiplying-dividing device 12 at the time of the peak maximum output. At the same time, from the output of the second pulse driver 9, a pulse arrives at the control input III of the analog-digital multiplier 12, and at the output bus of the analog-digital multiplier splitter 12 appears

01

 .

(one)

where K, is a constant coefficient.

The storage device 7 is set to the Record position, the analog-digital multiplying-dividing device 12 is set to the Analog-to-digital conversion position, and the pulse counter b is in the zero position. Switch 14 closes. Then a calibration mixture is introduced into the chromatographic column. At the same time, the signal of the detector 2 is amplified by the amplifier of the signal of the detector 3, then goes to the amplifier-limiter, forms from the signal acting on

If UQJ 5 is determined by expression (1), then this voltage is applied to the information input 11 of the analog-digital multiplier-dividing device 12 at the time of the peak maximum. At the same moment, a pulse arrives from the output of the second pulse generator 9 to the control input III of the analog-digital multiplier 12, and the output code N. Appears on the output bus of the analog-digital multiplier separator 12, defined by the expression

and

0

N..U ;,

(2)

where U- is the voltage, acting at the output of the amplifier 2 at the time of the peak peak. Since the relation is

U: K; -C

(3)

where C

s

K, the concentration of the 1st component of the calibration mixture; sensitivity factor-. these chromatographs to the i-th component of the mixture,

then from expressions (2) and (3) it is determined: in the code

DH ° K1 C about 1 K h f. . W - I L 1

I TT-V G V

Code N. enters the input bus of memory 7 and, therefore, is recorded in the memory at the i-th address. Thus, at the end of the last peak, codes are stored in the memory, the values of which are determined by the sensitivity coefficients K; components of the reference sample in accordance with the expression (4).

In the analysis mode of the test sample, the switch 14 is opened, the charger 7 is transferred to the Read mode, the counter 6 and the shift register 10 are set to the zero position, the analog-digital multiplier-divider 12 is switched to the Digital-to-analog conversion mode.

The sample to be analyzed is then introduced into the chromatographic column. At the time of the beginning of the i-ro peak at the outputs of counter 6, a code is set to 1, therefore, the code written at the address, i.e. NJ code This code is fed to the input bus analog-digital multiplying-dividing device 12 that implements the function

and

out

 Ni and;

(five)

13 is determined by the concentration of the component and does not depend on the magnitude of the sensitivity coefficient.

If in the voltage calibration mode and ,, taken from the potentiometer block, set equal to each other (DO, - Ujj), then all the peaks on the chromatogram will be the same

quantities.

In this case, the device can be used for the purposes of normocontrol, since with differences in the concentrations of the components of the calibration and anapizable probes on the chromatogram in the analysis mode will be different height. When the concentration of the i-ru component is exceeded in the mode of analyzing the concentration of this component in the normalization

For the sample used in the calibration mode, the amplitude of the i-ro peak exceeds the voltage U applied to one input of the comparator 15, the comparator 15 is activated and turns on the sound or light alarm 16.

When using the device for automatic air pollution control, labor protection is improved due to the possibility of

operational information on the conversion of concentrations of harmful substances and substances in the air of industrial premises.

where and gj, is the voltage at the analog output of the analog-digital multiplying-dividing device;

 - the voltage at the output of the amplifier 2 signal is detected. ra,

At the time of the peak output of the i-ro peak, the voltage at the output of the analog-digital multiplier-separating device is equal to

Uem N; U, it-к, c, K, -CX;. (6)

where Cjf- is the concentration of the i-ro component of the analyzed mixture. Thus, when the top of the i-ro component leaves, the sample is analyzed, the voltage at the analog output of the analog-digital multiplier-separator device 12 is proportional to the concentration of this component, and the height of the corresponding peak on the chromatogram recorded by the recorder

35

Claims (1)

Invention Formula A device for recording chromatograms containing a recorder and a detector connected in series, signal amplifier of the detector, limiting amplifier, pulse shaper, pulse counter, characterized in that, in order to speed up the registration process and reduce the complexity of processing the results, it introduced an analog-digital multiplying-dividing device, a memory device, a differentiator, the second driver pulse, shift register, up-switch, potentiometer block, key, comparator, alarm device, with the outputs of the pulse counter connected to the address bus of the memory device, the storage bus of the storage device is connected to the input of another analog-digital multiplying device, the output bus of the analog-digital multiplying-dividing device is connected to the input bus of the storage device, the output of the detector signal ycRp is connected to one information input of the analog-digital multiplying device , as well as through a series-connected key - with the input of the differentiator, the output of the differentiator is connected to the input of the second pulse shaper, the output The second pulse shaper is connected to the input of the shift register, as well as to the control input of the analog-digital multiplying-dividing device. Fke. Compiled by I.SokolOb. Editor V.Danko Tehred M.Morgental Order 5799/38 Circulation 789 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 the outputs of the shift register are connected to the control inputs of the analog switch, the outputs of the potentiometer block are connected to the information inputs of the analog switch, the output of the analog switch is connected to the second information input of the analog-digital multiplying-digital device 0, the analog output of the analog-digital multiplying-dividing device is connected to the input of the recorder, as well as with the input of the comparator, the output of the comparator is connected to the signal 15. FI.2 Proofreader A. Obruchar Subscription