SU836572A1 - Device for determining microquantities of elements - Google Patents

Description

one.

The invention relates to the design of devices for introducing samples into atomic absorption spectrometers and can be used in the determination of trace amounts of various elements by the method of flameless atomic absorption spectrometry.

A device is known for determining the micro-quantities of elements containing a reaction mixture, an atomizer and a pipeline connecting the cell with the atomizer l.

It is also known a device for determining the micro quantities of elements by the method of flameless atomic absorption spectrometry, containing a reactive cell, solvent inlet pipes connected to a cell, a carrier gas inlet pipe lowered into the cell, a dispenser connected to an inlet pipe to add liquid, an atomizer with a gas inlet nozzle, made in the form of a pipe with a heater, and a pipeline connecting the upper part of the cell with a gas valve for gas input 2.

In known devices, the design of the reactionary cell1 does not provide for the quick and complete separation of the determined elements from the samples.

In addition, the use of a corundum tube located between the reaction cell and the atomizer and used for the preliminary thermal decomposition of volatile compounds of the elements being determined, can lead to their loss.

The design of the atomizer is known. The device is a quartz or graphite tube open on both sides with a hole in the middle for introducing the products of thermal decomposition of isolated volatile compounds. Loss of vapors of free atoms occurs through the open ends of the atomizer, as a result of which the sensitivity of their determinations is further reduced.

In order to speed up the determination by improving the biasing process of the reagents, the solvent inlets are connected tangentially to the bottom of the cell and are located

5 towards each other. In addition, the atomizer is provided with a window fixed at one of its ends, to which there is an outlet for the input of gas, and the atomizer and the window are made of quartz.

The drawing shows the technological scheme of the device.

A device for determining the micro quantities of elements by flameless atomic absorption spectrometry consists of reaction cell 1, connecting pipes 2 for introducing a solvent connected to a cell l connecting pipe 3 for introducing a carrier gas, dipped into cell 1, a dispenser 4 connected to connecting pipes 2 for introducing a solvent , an atomizer 5 with a nozzle b for introducing gas, made into a pipe with a heater 7 and a pipeline 8 connecting the upper part of the cell 1 with a nozzle 6 for introducing gas. The solvent inlets 2 are connected tangentially to the lower part of the cell and are arranged opposite to each other. The atomizer 5 is provided with a window 9 fixed at one of its ends, to which is attached a pipe 6 for introducing gas, the atomizer 5 being made of quartz.

The device works as follows.

The sample of the analyzed material is dissolved, an aliquot part of the solution is placed in the cell 1 with the cover removed 10, the necessary reagent additives are added to create the preconditions for the formation of hydrides, the cover 10 is closed and the magnetic stirrer 11 is turned on. syringe and flexible hose 13 take up sodium borohydride solution. The tank 12 in the section 14 is attached to the reaction cell 1. Cell 1 is pressurized with an inert gas stream, after which a metered amount of sodium borohydride is introduced into it. The gaseous element hydrides and products of the reaction with an inert gas stream are fed through a pipe 8 to the preheated Electrothermal atomizer 5, where the thermal decomposition of hydrides occurs and the formation of free atoms of definable elements recorded by an atomic absorption spectrometer.

The use of the proposed device will allow to increase the sensitivity and reproducibility of element determinations due to optimization of hydride formation and targeting and increase in the residence time of free atoms of the determined elements in the absorption zone of the half-closed atomizer.

Claims (3)

1. A device for determining microcolicheste of elements using flameless atomic absorption spectrometry, containing (a reaction cell of a solvent inlet, connected to a cell, a inlet for introducing a carrier gas, dispensed into a cell of a dispenser connected to a solvent inlet, an atomizer with a gas inlet pipe, made in the form of a pipe with a heater, and a pipeline connecting the top of the cell with a gas inlet pipe, This is due to the fact that, in order to speed up the determinations by improving the process of mixing the reagents, the solvent inlets are connected tangentially to the lower part of the cell and are located opposite to each other. 2. A device according to claim 1, characterized in that the atomizer is provided with a window fixed to one of its ends, to which is connected a gas inlet nozzle. 3. The device. Under item 1, about t l and - that the atomizer and a window are made of quartz. Sources of information taken into account in the examination. 1. For the VCA. Germany No. 2640285, class 42e, 3, 1978. 2.J. Foreman and P. Stockwell. Automatic chemical analysis. M., Mir, with. 180-196 (prototype). 7 - // y / xx / / X / Onmv "fffi (of ЯЯ cne mjyof fffflff