SU890085A1 - Nuclear absorption spectrophotometer burner - Google Patents

Description

one

This invention relates to atomic absorption spectroscopy and is intended to be used in conjunction with atomic absorption spectrophotometers for the elementary analysis of biological agricultural, metallurgical and other industrial samples.

Known slot burners for atomic absorption spectroscopy with a length of 5-10 cm til.

The closest to the proposed technical solution is a single-gap burner with an elongated and wider slit 2.

However, the urination of the liner or the widening of the burner gap, in order to increase the sensitivity, is accompanied by an increase in the flow rate of the combustible gas mixture, which makes this method uneconomical.

The time of the presence of free atoms in the volume of a flame illuminated by a ray of light is short, owing to the fact that free atoms move along with the gases of the flame perpendicular to the ray of light. Therefore, the sensitivity of the flame atomic absorption spectroscopy method is reduced, the free atoms formed

in a flame, they are distributed throughout the volume of the flame so that the proportion of atoms simultaneously involved in the process of absorbing light is small.

 The aim of the invention is to increase the sensitivity of the method without increasing the gas flow rate.

This goal is achieved by the fact that

10 a burner for an atomic absorption spectrophotometer comprising a burner housing, a chamber for feeding a combustible mixture, a slit for exiting the mixture from the chamber and creating a long flame, to

15 to the burner body are attached two coaxially spaced relative to each other hollow cylinders, forming an annular slit for receiving a cylinder of a first flame, and a screen;

Claims (2)

20 with an orifice for passing a beam of light through the flame along the axis of the cylinders, the external cylinder being attached to the burner body for displacing the internal cylinder to adjust the flame shape, and the screen for adjusting the flame length attached to the burner body to move along the axis of the cylinders, in addition , a flat-ended tube is connected to the screen of the bottom of the charger for flushing the flame with a jet of air. Figure 1 shows the burner, a vertical section; in fig. 2 burner, top view. The burner includes a housing 1 for supplying a combustible mixture of gases to the slit 2 for creating a cylindrical flame. Objective 2 is formed by two hollow cylinders 3 and 4 located coaxially to each other. In addition, the cylinders 3 4 also serve to prevent the flame from entering the interior of the burner. The opening 5 is intended to pass a beam of light in the flame from the light source 6. A metal screen 7 is attached to the burner body to prevent hot gases of the flame (combustion products) from entering the monochromator 8. The screen 7 is attached to the housing with the help of rods 9 and 10 with the ability to adjust the length of the flame. The hole 11 on the screen 7 is designed to pass a beam of light to the monochromator. A metal tube 12 is attached to the screen 7 below and attached to the jet of air that prevents the combustion products from entering the hole 11. For this, the end of the tube is made flat and perpendicular to the beam of light (gas movement flame). The arrows indicate the direction of movement of the gases of the combustible mixture and the gases of the flame. The burner works as follows. The combustible gas mixture through the housing i feeds 9 to the slit of the burner 2. The gases leaving the slit 2 are ignited to form a cylindrical flame that extends along the length to the metal screen 7. To change the rate of release of the combustible mixture from the slit 2 of the burner, the outer cylinder 4 is attached to the housing with the possibility of movement along the inner cylinder 3. A stream of air emerges from the tube 12 with a flat end, which prevents the flame from propagating into the aperture 11 to the monochromator 8. The distribution of the rest of the flame gases limits screen 7 so that finally products of the combustion move upwards. The length of the flame can be adjusted by means of rods 9 and 10, the change in sensitivity of the measurement, depending on the sample under study. Light from the light source b through hole 5 passes into the central part of the flame and passes through hole 11 to the monochromator 8. This burner design makes it possible to increase the optical path traversed by the light beam in the flame, and thereby improve the sensitivity of the method without increasing the flow rate of the combustible gas . An inventive burner for an atomic absorption spectrophotometer comprising a burner body, a chamber for feeding a combustible mixture with a slit for leaving the mixture out of the chamber, characterized in that, in order to increase sensitivity without increasing gas flow, two coaxially spaced relative to each other are attached to the burner body another hollow cylinder forming an annular gap to produce a cylindrical flame, and a screen with a hole along the axis of the cylinders, with the outer cylinder attached to the burner body with the possibility of The displacement is along the inner cylinder, and the screen is attached to the burner body so that it can be displaced along the axis of the cylinders, and a flat-ended tube is connected to the screen for blowing the flame with an air jet. Sources of information taken into account in the examination 1.Lvov B.V. Atomic absorption spectral analysis. Science, M., 1966, p.196. 2.Slavin V. Atomnb-absorption spectroscopy L., Khimi, 1971. eight