SU1352356A1 - Device for determining aggregate organic carbon in water media - Google Patents

Abstract

The invention relates to analyzers of total organic carbon in aqueous media and allows an increase in the instrument speed and sample dosing accuracy. The device contains a device for supplying and stabilizing steam, a device for preparing and metering a sample in the form of a metering loop, hermetically connected to two strokes of an eight-way valve, the remaining strokes of which are connected by a vaporizer through a filter to hold mineral impurities, with a clean steam line , with a clean vapor discharge line, with an overpressure discharge line from the metering loop, with a stable source of inert carrier gas or water vapor, and with a flame ionization detector. The instrument allows analysis in less than 1 minute. Accuracy of dosing is at least 2%. The design of the device allows the purging of all sample preparation lines during the analysis of a - the previous sample. I Ш1. O) co-eaten oo ate 05

Description

The invention relates to analyzers of impurities in natural and waste waters and can be used to determine the content of total organic carbon in aqueous media.

The aim of the invention is to increase the speed and accuracy of the analysis.

The drawing shows the proposed device.

The device contains a device for supplying and stabilizing the flow rate of an inert carrier gas or water vapor, which is a carrier, consisting of gas 1 with compressed gas (nitrogen, argon, helium), gear 2, model man 3, needles valves 4, 5 and 6, tank 7 with bidistilled water connected through a metal capillary p 8 with a length of 8–12 m serving to resist the flow of water, k; a superheater 9 connected to a stabilizing column 10 and a buffer tank 11, a device for preparing and dosing a sample, made in the form of a metering loop 12, hermetically connected to two strokes of an eight-way valve 13, the remaining strokes of which are reego connected respectively to an evaporator 14 through the filter 15 to hold the mineral impurities contained in the sample (the evaporator 14 has an additional pressure release line 16), with a clean steam purge line 17, a clean steam discharge line 18, an overpressure discharge line 19 and from the metering loop, with a source of a stable stream of inert carrier gas or water vapor from the buffer tank 11 and with a hydrogen flame ionization detector 20 (DIP) through an additional resistance made in the form of a metal capillary 21 with a length of 6–15 m detecting organic impurities contained in a metered volume of inert gas or water vapor, including a hydrogen flame ionization detector 20, a hydrogen source 22, and an air source 23, a small current measurement unit 24,

45 mosfere When dosing a sample, no irregularity of the steam flow through DIP 20 is disturbed since the flows of pure steam and sample vapor do not touch each other. The registrar 25 records a flat zero line. The purge steam through line 17, the channel of the 8-way valve 13 and the clean vapor discharge line 18 is vented to the atmosphere. All discharge lines are recorded on the recorder 25 and integrated diffraser 26,

The device works as follows, igg dts in the thermostat 27 at 60–180 ° C. Inert gas from the cylinder 1 of the gearbox. When the device is set to the position rum 2 at a known pressure measured by an exemplary manometer 3, with the needle valves 4 and 5 open and

analysis of the sample (after 15 s, after the sample is introduced into the evaporator), the clean water vapor from the buffer tank 11 enters

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the closed valve 6 is fed into the tank 7 with bidistilled water, from which water flows at a speed determined by the applied pressure through a metal capillary 8 enters the superheater 9, from where water in the form of pure water vapor enters the stabilizing column 10 filled with pure granular silica, and then through the buffer tank

11- in the vsmikhodovy crane 13,

When setting the instrument to the sample dispensing position, the metering loop

12 is not included in the flow line of pure water vapor, which, through the channel of the 8-way valve 13, directly from the buffer tank 11, through an additional resistance, made in the form of a metal capillary 21, enters DIP 20. The sample being analyzed is introduced into the evaporator 14, where it evaporates at 260-300 ° C; sample vapor pressure

5 becomes higher than atmospheric

by which the vapors of the sample fill the dosing loop 12 having a fixed volume. The excess vapor pressure of the sample in 5–8 s decreases to atmospheric, since the sample vapors through the discharge lines 16 and 19 are released into the atmosphere. If the water being analyzed contains mineral impurities, they are captured in filter 15. Most of the sample’s sample is discharged through line 19, which, together with filter 15, has less pneumatic resistance than the additional pressure release line from the evaporator 14, therefore metering loop 12 is always filled It is earlier than the pressure inside the evaporator 14, the filter 15 and the metering loop 12, which constitute one total volume, and the atmosphere are equalized. When dosing a sample, there is no disturbance to the steam flow through DIP 20, since the clean steam and sample vapor flows do not touch each other. The registrar 25 records a flat zero line. The purge steam through line 17, the channel of the 8-way valve 13 and the clean vapor discharge line 18 is vented to the atmosphere. All reset lines are found0

dts in thermostat 27 at 60-180 ° C. When the instrument is set to

analysis of the sample (after 15 s, after the sample is introduced into the evaporator), the clean water vapor from the buffer tank 11 enters

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into the metering loop 12 through the channel of the 8-way valve 13, flushes out the dosed volume of the sample in the loop and through another channel of the 8-way valve 13 and additional resistance 21 Carries the sample to be analyzed to the DNI 20 where the organic substances contained in the sample are detected. It is known that DIP is very sensitive to microscopic organic matter, and the DIP signal depends linearly on the content of organic matter when the concentration of

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for 6-7 times dkov. The presence of a large-15 silica-filled Silochrome C-80

The amount of water vapor in the sample does not affect the stability of the zero line of the detecting device, since the carrier gas is also water vapor. The maximum time for the sample to exit (before the pen returns to the self-, scribe on the zero line) at a flow rate of 60 cm / min of water vapor does not exceed 30 s. Thus, the total analysis time after the sample has been introduced into the evaporator is 25 17 () C, and the superheater 9 has a metering body 14 of a known volume, on the lid of the thermostat 27 and is connected

grain size of 0.16-0.25 mm, which is at 420 ° C, a stabilizing column 10, inside a thermostat at 170 ° C and filled with the same 20 silica, and a buffer tank 11 with a volume of 150 cm, connected to a stabilizer D its column, which is also inside the thermostat for the LHM-8MD borator chromatograph with

determined by the volume of the metering loop 12, and the passage of this volume through DIP 20 does not exceed 1 min. In this case, clean steam through the purge line 17 and the channel of the 8-way valve 13 washes away the remnants of the last introduced sample from the filter 15 and the evaporator 14, releasing them into the atmosphere through the discharge line 16. Since the pneumatic resistance of the filter 15, the evaporator L4 and the discharge lines 16 are 3 times less than the additional resistance 21, the flow rate through the nodes 14, 15 and 16 is 3 times higher than through the node 21, therefore during the analysis of the sample the evaporator is ready to enter the next sample. After completion of the sample analysis, the instrument is transferred.

In the sample dosing position and the stainless steel tube is repeated. The meter is 3 mm long and B cm in length. The design of the proposed instrument with 0.16-0.25 mm granulation gel allows to purge all of the purge line 17. steam, you are a pure inert gas carrier full of a tube (stainless steel)

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to free them from water vapor. This is achieved by the fact that when the needle valves 4 and 5 are closed and the needle valve 6 is open, the water supply to the superheater 9 is stopped, and the water vapor remaining in the gas lines inside the thermostat 27 is blown out with an inert gas.

Example. The concentration of benzene in water was determined using 55

with an inner diameter of 1 mm and a length of 50 cm, with a clean vapor discharge line 18 made of a metal capillary with a length of 6 m and a diameter of 0.5 mm with a source of inert carrier gas or water vapor of the discharge line 16 with a length of 5 m and an internal diamter 0.5mm and discharge line 19 from a metering loop 0.5 m long and with an inner diameter of 0.5 mm l are also made of metal-jg

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whether the device containing the cylinder 1 with nitrogen, the reducer c. pressure gauges for 150 and 15 kgf / cm, an exemplary manometer 3 for 10 kgf / cm, needle valves 4, 5 and 6, a container 7 with bidistilled water, containing 0.4 liters of liquid, a metal capillary tube 8 with an internal diameter of 0.5 mm and a length of 12 m to create resistance to the flow of water coming from the tank 8 to the superheater 9, made in the form of a stainless steel tube with an inner diameter of 6 mm and a length of 150 mm, for 17 () C, and the superheater 9 is located on the cover of the thermostat 27 and connected

grain size of 0.16-0.25 mm, which is at 420 ° C, a stabilizing column 10, which is inside the thermostat at 170 ° C and filled with such silica, and a buffer tank 11 with a volume of 150 cm, connected with a stabilization is located inside the thermostat of the LHM-8MD laboratory chromatograph with

a short tube of 50 mm and an internal diameter of 2 mm, which is thermally insulated to prevent condensation

30 water vapor generated in the superheater 9 and entering the stabilizing column under the pressure of 4.5 atm with a bulk velocity of 100 cm / min,

A sample preparation and dosing device in the device contains a dosing loop 12 made of a capillary (stainless steel) with an internal diameter of 2 mm and a length of 2 m, tightly connected to two strokes of the serial 8-way valve 13, the remaining strokes of which are connected to vaporizer

14th chromatograph through filter

15dl retention of mineral impurities, which are metal35

silica gel granulation 0.16-0.25 mm with purge line 17 clean steam, completed -from the tube (stainless steel)

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with an inner diameter of 1 mm and a length of 50 cm, with a clean vapor discharge line 18 made of a metal capillary with a length of 6 m and a diameter of 0.5 mm with a source of inert carrier gas or water vapor of the discharge line 16 with a length of 5 m and an internal diamter 0.5 mm and discharge line 19 from a metering loop 0.5 m long and inner diameter 0.5 mm l are also made of metal capillaries), with DIP 20 through additional resistance 21 made of a metal capillary 12 m long and inner diameter 0, 5 mm. The DIP uses a domestic ionization detector in a hydrogen flame, which is installed in LHM-8MD chromatographs and has a guaranteed detection limit (sensitivity threshold) 2 ,.

A 5 µl sample is injected with a 10 µl syringe. The benzene concentration in the test solution is 10 µg / l water. During sample entry, the 8-way valve is in the Sample Dosing position. The analyzed sample evaporates in the evaporator, in which 300 ° C is maintained, the sample vapors fill the metering loop 12, the excess pressure drops to 7 seconds to atmospheric pressure by dropping a portion of the sample through lines 16 and 19. Thus, in the metering loop at atmospheric pressure strictly fixed volume on the value of which does not affect the error during the introduction of a certain volume of liquid in the evaporator.

After switching the V-run valve to the position Analysis of the sample after 15 seconds of input to the evaporator, the pure WATER vapor transfers the analyzed 5 sample to DIP 20 where the organic substances contained in the sample are detected. The deviation of the pen of the KSP-4 recorder with a scale of 1 mV is 20 mm with the sensitivity of the amplifier 20-10 A, which is 5 times higher than

device noise. The time of the full analysis from the moment the sample is introduced into the evaporator is 45 seconds.

The calculation of the experimental data shows that the accuracy of the analysis of the sample by the proposed instrument is 2% against 20% known. The time required for analysis does not exceed 1 minute versus 3 minutes with a known instrument.

Claims (1)

Invention Formula A device for determining total organic carbon in aqueous media containing a steam generator with a filter and a flow controller, a dosing device, a capillary resistance connected to a detector, a recording device and a discharge line, characterized in that, in order to increase the efficiency and accuracy of analysis, the steam generator further comprises a superheater, a stabilizing column and a buffer tank, the metering device is designed as an eight-way valve with a metering loop, hermetically connected to two its passages, and the rest of its moves are connected through an additional filter with a sample vaporizer, which has an additional steam discharge line, a steam generator, a clean steam discharge line, additional pure steam blow lines, an overpressure relief, and a resistance through a detector.