SU1399776A2 - Device for measuring the area of chromatography peak - Google Patents

Abstract

The invention relates to the field of automation and computing technology. The aim of the invention is to improve the accuracy of determining the areas of chromatographic peaks by taking into account their expansion over time of analysis. The device for determining the area of the chromatographic peak contains a delay unit 1, a peak amplitude determination unit 2, a comparator 3, memory blocks 4.5 and 6, division blocks 7 and 10, a logarithm calculation unit 8, a square root extraction unit 9 and a multiplication unit 11. The principle of operation of the device is based on fixing the moment of equality of the input and delayed signals from the output of the chromatograph detector. Accuracy increase is achieved by increasing the signal delay time during the analysis process and corresponding correction of the result of calculating the area of the current muck. 3 il. (L

Description

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The invention relates to automation and computing, in particular, can be used in devices for automatic processing of chromatographic information and is an improvement of the known device according to the author. St. No. 970391.

The purpose of the invention is to improve the accuracy of determining the areas of chromatographic peaks by taking into account their expansion over time of analysis.

FIG. 1 shows a block diagram of an apparatus for determining the area of a chromatographic peak; in fig. 2 - variant of the source (block) setting of the delay time; FIG. 3 shows timing diagrams explaining the operation of the device.

A device for determining the area of the chromatographic peak (Fig. 1) contains a delay unit 1, a peak amplitude determination unit 2, a comparator 3, first to third memory blocks 4.5 and 6, a first division unit 7, a logarithm calculation unit 8, unit 9 extracting the square root, the second division unit 10, the multiplication unit 11, and the input 12 of the task delay device setting. The source of the time delay (Fig. 2) can be performed on the pulse generator I3, the counter 14, the decoder 15 and the block} 6 keys.

The operation of the device is based on determining the peak areas of the chromatograms by delaying the signal from the detector output and calculating the result using the analytical expression h

.

:,; K j | | u; t, (1)

l | -1n where h is the peak amplitude;

h is the function value at which

peak width is numerically equal

delay time (s); (U is the width of the peak measured at

level c - the set value is

handles.

In this case, the adjustment of the delay time is carried out, since the chromatographic peaks tend to expand over the course of the analysis (Fig. 3a). Indeed, as can be seen from Fig. 36, the use of the same delay time of peaks P1 and P2 leads to inaccuracies in determining the area of peak P2 by expression (1) due to the difficulty of fixing h and bringing together the values of h and h. The stronger

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five

0 5 o

five

0

five

0 5

 the peak is flattened, the error in determining its area is greater because

 j, - (2)

  l | -1p hVh

From FIG. It can be seen that with an increase in the delay time for a wide peak of the RE, the error decreases. The delay is controlled during what is in the analysis: for example, the time interval t, (Fig. 3a) corresponds to the delay value T,, respectively, H, etc. depending on the duration of the analysis.

The device works as follows.

At the beginning of the analysis, the generator 13 pulses of the source (block) of the control of the delay time starts, the filling of the time counter 14 starts. the key block 16 and the corresponding capacity (or resistance) included in the delay block 1 is put into operation (the technical implementation of the delay time control block does not have In principle, in particular, the delay unit and the delay time adjustment unit may be replaced with an adjustable delay line). At the same time, a sample is taken from the third memory block 6 of the corresponding value of the coefficient K, which is fed to the second input of the multiplication unit 11.

The amplified signal from the output of the chromatograph detector is fed simultaneously to the input of the delay unit 1, the input of the peak amplitude determination unit 2, to the first input of the comparator 3 and to the information inputs of the first 4 and second 5 memory blocks. At the moment when the input signal reaches its amplitude value, block 2 determines the amplitude of the peak, the signal of which allows storing the value of the input voltage corresponding to the height of the peak h, which enters the information input of the first memory block 4. At the moment of equality of the input. And the delayed signal triggers the comparator 3, on the signal of which the value of the function corresponds to the corresponding coefficient K

This moment (h) is memorized in memory block 5. Blocks 7-10 consistently perform mathematical operations in accordance with formula (I). The resulting re-resultant h / -} - ln goes to the first input of block P multiplication, where it is multiplied

.

one

the value of which varies with the analysis in parallel with the change in the value of the delay.

Thus, the considered device allows to increase the accuracy of determining the areas of chromatographic peaks in comparison with the prototype by taking into account the tendency to expand over the course of the analysis of real peaks of chromatography by adjusting

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the delay time and the corresponding correction of the calculation result. This, in turn, leads to improved accuracy and efficiency of quantitative chromatographic analysis.

Claims (1)

Invention Formula A device for determining the area of the chromatographic peak - according to ed. No. 970391,: about the fact that, in order to improve the accuracy of determining the areas of chromatographic peaks by taking into account their expansion over time of the analysis, a third memory block, connected by an address input, was inserted into it the input specifies the device delay time, and the output to the second input of the multiplication unit. (rig 2. Out but 6 figs