Basic introduction and daily maintenance of atomic fluorescence photometer

The atomic fluorescence photometer uses an inert gas argon as a carrier gas, mixes the gaseous hydride and excess hydrogen with the carrier gas, and then introduces it into a heated atomization device. The hydrogen and argon are burned and heated in a special flame device, and the hydride is heated rapidly. Decomposition, the measured element dissociates into the ground state atomic vapor, and its ground state atom is several orders of magnitude higher than the ground state atom generated by heating elements such as arsenic, antimony, bismuth, tin, selenium, tellurium, lead, and antimony.

A method for qualitative and quantitative analysis of a substance using the wavelength and intensity of an atomic fluorescence line. After the atomic vapor absorbs the characteristic wavelength of the radiation, the atom is excited to a high energy level, and the excited state atom is then deactivated by radiation. The light emitted during the transition from the high energy level to the lower energy level is called atomic fluorescence. When the excitation source stops illuminating, the process of emitting fluorescence stops. Atomic fluorescence can be divided into three categories: resonance fluorescence, non-resonant fluorescence, and sensitized fluorescence, in which resonance atomic fluorescence is strong, and Zui is widely used in the analysis. The resonance fluorescence is the same as the emitted fluorescence and the absorbed radiation. Resonance fluorescence can only be produced when the ground state is a single state and there is no intermediate energy level. Non-resonant fluorescence is the wavelength of the fluorescence emitted by the excited state atoms and the wavelength of the absorbed radiation are not the same. Non-resonant fluorescence can be further divided into straight-line fluorescence, step-line fluorescence, and anti-Stokes fluorescence. The direct jump fluorescence is the fluorescence produced by the transition of the excited state from a high energy level to a metastable energy level above the ground state. The step line fluorescence is that the excited state atom first deactivates the lost part of the energy in a non-radiative manner, returns to the lower excited state, and then deactivates the fluorescence emitted by the transition to the ground state by radiation. Both the straight line and the step line have wavelengths that are longer than the wavelength of the absorbed radiation. Anti-Stokes fluorescence is characterized by a shorter wavelength of the fluorescence than the wavelength of the absorbed light radiation. Sensitized atomic fluorescence is the fluorescence that an excited atom emits excitation energy by collision to another atom to excite it, which is then deactivated by radiation.

Qualitative analysis can be performed based on the wavelength of the fluorescent line. Under certain experimental conditions, the fluorescence intensity is proportional to the concentration of the element being measured. According to this, quantitative analysis can be performed. Atomic fluorescence spectrometers are classified into two types: dispersion type and non-dispersion type. The structure of the two types of instruments is basically similar, the difference is that the non-dispersive instrument does not use a monochromator. Dispersive instruments consist of a radiation source, a monochromator, an atomizer, a detector, a display and a recording device. A radiation source is used to excite atoms to produce atomic fluorescence. A continuous light source or a sharp line light source can be used. The commonly used continuous light source is a xenon arc lamp. Available sharp line sources include high-intensity hollow cathode lamps, electrodeless discharge lamps, and temperature-controlled atomic spectrum lamps and lasers. The monochromator is used to select the desired fluorescence line and to exclude interference from other spectral lines. The atomizer is used to convert the measured elements into atomic vapors, with flame, electrothermal, and inductively coupled plasma flame atomizers. The detector is used to detect the optical signal and convert it into an electrical signal. The commonly used detector is a photomultiplier tube. The display and recording device is used to display and record measurement results, such as an electric meter, a digital meter, a recorder, and the like. Atomic fluorescence spectrometry has the advantages of simple equipment, high sensitivity, less spectral interference, wide linear range of working curve, and multi-element measurement. It has been widely used in various fields such as geology, metallurgy, petroleum, biomedicine, geochemistry, materials and environmental science.

Daily maintenance of atomic fluorescence photometer

● Strictly follow the opening and closing procedures.

● Observe the sealing performance of the pipeline. If the pipeline leaks, stop the pump in time, check the leak source and connect the pipeline again. The liquid should be removed in time to avoid liquid corrosion on the surface of the instrument.

● Please dispose of the waste in time for your own health and environment.

● After the test is completed, clean the pump tube and the injection needle with deionized water, and remove the peristaltic pump tube tube card in time to avoid the long-term compression deformation of the pump tube and affect its life. After deformation, it can be immersed in 10% hydrochloric acid for 48 hours, and washed with deionized water for use.

● After the pump tube has been used for a period of time, the supplied silicone oil should be added to the gap between the pump tube and the pump head at any time to protect the pump tube.

● Surface cleaning of the instrument The surface of the outer casing of the instrument has been painted and sprayed. Please do not leave the solution on the outer casing during use. Otherwise, it will leave marks on the outer casing. If you accidentally spill the solution. Immediately wipe the case with a damp towel and wipe it off with an organic solution.

● The gas-liquid separator and the heated quartz tube are quartz glass pieces. Avoid collision to avoid breakage. Use 10% hydrochloric acid for 24 hours to remove impurities during use. Clean and dry with deionized water.

● When the instrument is not used for a long time, it is necessary to preheat the instrument every half an hour or so (preheating in the measurement state is useful), which helps to extend the life of the lamp and the instrument.