SU1608576A1 - Flame-ionization detector - Google Patents

Abstract

The invention relates to gas chromatography, in particular, to detection devices used for the analysis of organic substances, and can be used in the practice of analytical and research work. The purpose of the invention is to increase the detection sensitivity. The detector has a housing with fittings for the supply and removal of gas. A burner serving as a potential electrode, a collector electrode and an ignition element of the burner are located in the housing. Through a 2-position switch, the ignition element is alternately connected to a power source and a collector electrode. 1 ill., 1 tab.

Description

AND;

The acquisition relates to gas chromatography, in particular, to detection sticks used for the analysis of .IX organic substances, section e- chromatographic columns, and to be used in practice and research

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The principle of the invention is the improved detection of the stability of the results, the figure shows a flame ionization detector.

The detector contains a cylindrical 1, made of electrolytic cyclic material, on a section of the inner surface of the casing by means of a single coating or other methods) metal layer 2 on the current-conducting layer introduced into the pores of the electrolytic material, which

performs the functions of a measuring electrode 3 with a terminal connected to an electrometric amplifier. The burner 4, made of electrically insulating material, has a metallized nozzle, a metal layer 5 of which is deposited on a conductive layer inserted into the pores of the electrically insulating material, which functions as a potential electrode 6 with a terminal connected to a power source. The housing 1 is on top closed with a cover 7 of electrically insulating material, in which is placed a coil 8 for igniting the flame. The base 9 has fittings for supplying air 10, for supplying hydrogen 1 G and for supplying carrier gas 12, the upper metal flange 13 has a fitting 14 for exiting the combustion products. The parts are connected with nuts by means of studs 15 into a block and form an ionization chamber 16. A measuring electrode terminal 3 is connected

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a yen with contacts 1 of switch 17, and the output of ignition coil 8 is connected through the middle contacts of switch 17 with power supply 18.

The detector works as follows.

Air is supplied through the fitting 10 to the detector, and hydrogen through fitting 11 which feeds and maintains the flame on the burner nozzle 4. The flame is ignited by coil 8 in the position of the switch 17 when the middle electrodes are closed in position 2 due to the ignition voltage power source 18. Through fitting 12 into the ionization chamber 16 of the detector, together with the carrier gas, the sample components that fall into the flame of a hydrogen burner undergo ionization from the chromatographic column, resulting in an ionization current, the value of which is proportional to the number of charged particles. The arising electrical signal through the terminal of the measuring electrode 3 and the ignition coil 8, connected by the contact 1 of the switch 17, is fed to the amplifier and recorded on a recording potentiometer in the form of a chromatogram.

The test results are shown in the table.

Formula aizobre re shadow

Flame ionization detector, comprising a housing with channels for the supply and output of gases and placed in it a burner that serves as a potential electrode,

a collector electrode, as well as a burner ignition element connected to a power source or to one of the electrodes through a two-position switch of contacts, characterized in that

the purpose of increasing the detection sensitivity, the ignition element of the burner is connected to the collector electrode,

Indicators

Carrier gas (nitrogen) consumption, cm / min Hydrogen consumption, Air consumption, cm / min Evaporator temperature, ° C Temperature of the column thermostat, ° C Metal column:

length cm

diameter, mm

Sorbent - chromatone silanized SE-30,% impregnation

The control substance is a mixture of hexane in nano:

concentration, mg / ml

dose mcl

Supply voltage, V Background current, not more, A Level of fluctuating noise, A Threshold value of sensitivity, mg / s Tape speed of a potentiometer, mm / h

Values of indicators for the flame ionization detector

66

46

500

200

90

50 3

2.8 0.5 300

1.9 X 10 1.0 x 10 4.3 X 10- 600

-eleven

-14 10

Claims (1)

10 claims A flame ionization detector comprising a housing with channels for supplying and discharging gases and a burner located therein serving as a potential electrode, a collector electrode, and a burner ignition element connected to a power source or to one of the electrodes via a two-position contact switch, characterized in that, in order to increase the detection sensitivity, the burner ignition element is connected to the collector electrode, Indicators Values for the flame ionization detector The consumption of carrier gas (nitrogen), cm ³ / min 66 The consumption of hydrogen, cm ³ / min 46 Air consumption, cm ³ / min 500 Evaporator temperature ^ ° C 200 Column thermostat temperature, ° C 90 Metal column: length cm fifty diameter mm 3 Sorbent - chromaton silanized SE- 30% impregnation 5 The control substance is a mixture of hexane in nane: concentration, mg / ml 2,8 dose, mcl 0.5 Supply voltage 300 Background current, no more, A 1.9x10 ^-11 The level of fluctuation interference, A 1,0x10 ¹⁴ Sensitivity threshold value, mg / s 4.3 x 10- ¹⁰ Potentiometer tape speed, mm / h 600