Name: atomic absorption spectroscopy: key parts
Uploaded: 2025-05-22T09:06:10.000Z
Duration: 1 min 22 s
Channel: JoVE

Un espectrofotómetro de absorción atómica consta de una fuente de radiación, un atomizador, un monocromador y un detector.
La fuente de radiación suele tener un rango estrecho, como una lámpara de cátodo hueco, o HCL, o una lámpara de descarga sin electrodos, o EDL. Los instrumentos con fuentes de continuo utilizan monocromadores de muy alta resolución.
El siguiente es el atomizador, con métodos comunes que son la atomización de llama y la atomización electrotérmica. 
Algunos átomos se excitan térmicamente y emiten radiación. Esta interferencia se puede aislar mediante el uso de un picador mecánico entre la fuente y el atomizador para dar a las emisiones causadas por la radiación de la fuente un patrón de frecuencia constante distinto.
En un espectrofotómetro de haz único, la radiación pasa directamente a través de la muestra atomizada.
Un instrumento de doble haz divide el haz de la fuente. Un haz pasa a través de la muestra atomizada, mientras que el otro la evita. Luego, los dos haces se recombinan usando un espejo medio plateado.
Después, el haz pasa a través del monocromador, que envía solo un rango de longitud de onda estrecho al detector, por lo general, un tubo fotomultiplicador, que convierte la luz en señales eléctricas amplificadas.

espectroscopia de absorción atómica: instrumentación

Atomic Absorption Spectroscopy: Instrumentation

Un espectrofotómetro de absorción atómica (AAS) consta de varios componentes: una fuente de radiación, un atomizador, un monocromador y un detector. La fuente de radiación puede ser una lámpara de cátodo hueco (HCL) o una lámpara de descarga sin electrodos (EDL), las cuales proporcionan una línea de emisión estrecha de la longitud de onda requerida. Sin embargo, algunos instrumentos utilizan fuentes continuas y monocromadores de alta resolución para lograr un rango estrecho de radiación.

El atomizador utilizado en AAS puede ser un atomizador de llama o un atomizador electrotérmico. Los átomos en fase gaseosa generados por el atomizador a menudo se excitan térmicamente y emiten radiación, lo que causa una interferencia con la señal de la fuente de radiación. Se utiliza un disco metálico circular, llamado chopper, para eliminar dicha interferencia entre la fuente de radiación y el atomizador de llama. El chopper metálico aísla la fuente de radiación creando una señal alterna, a diferencia de la señal continua de la llama.

En un espectrofotómetro de haz único, la radiación pasa directamente a través de la muestra atomizada, mientras que, en un instrumento de doble haz, el haz de origen se divide, de modo que un haz pasa a través de la muestra atomizada y el otro es el haz de referencia. A continuación, los dos haces se recombinan utilizando un espejo semiplateado. El haz combinado pasa entonces por el monocromador, que permite que solo un rango estrecho de longitudes de onda llegue al detector. El detector suele ser un tubo fotomultiplicador que procesa y convierte la radiación en señales eléctricas amplificadas.

Espectroscopia de Absorción Atómica: Instrumentación

Un espectrofotómetro de absorción atómica (AAS) consta de varios componentes: una fuente de radiación, un atomizador, un monocromador y un detector. La radiación ...

atomic-absorption-spectroscopy-instrumentation

Education

Educación

JoVE Core

Analytical Chemistry

Química Analítica

Unit 1

Unidad 1

Atomic Spectroscopy

Espectroscopía Atómica

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

atomic absorption spectroscopy: key parts

Atomic absorption spectrophotometry uses a set of key parts to measure light absorbed by atoms. The main components are a radiation source, an atomizer, a monochromator, and a detector. Each part has a specific job in the instrument.

The radiation source is usually a hollow-cathode lamp, or HCL, or an electrodeless-discharge lamp, or EDL. Both produce a narrow emission line at the needed wavelength. Some instruments instead use continuum sources with high-resolution monochromators to narrow the radiation range.

The atomizer turns the sample into gas-phase atoms. It can be a flame atomizer or an electrothermal atomizer. At times, these hot atoms also emit radiation, which can interfere with the signal from the radiation source.

A circular metal disk called a chopper helps reduce that interference with a flame atomizer. The chopper makes the source beam into an alternating signal. This is different from the continuous signal from the flame.

AAS instruments can also be single-beam or double-beam systems. In a single-beam spectrophotometer, the radiation passes directly through the atomized sample. In a double-beam instrument, the source beam splits into a sample beam and a reference beam, and a half-silvered mirror recombines them.

After recombination, the beam passes through the monochromator. The monochromator allows only a narrow wavelength range to reach the detector. The detector is usually a photomultiplier tube, which converts the radiation into amplified electrical signals.

Atomic Absorption Spectroscopy: Key Parts

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atomic absorption spectroscopy: instrumentation

Atomic absorption spectrophotometry uses a set of key parts to measure light absorbed by atoms. The main components are a radiation source, an atomizer, a monochromator, and a detector. Each part has a specific job in the instrument. The radiation source is usually a hollow-cathode lamp, or HCL, or an electrodeless-discharge lamp, or EDL. Both produce a narrow emission line at the needed wavelength. Some instruments instead use continuum sources with high-resolution monochromators to narrow...

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atomic-absorption-spectroscopy-radiation-and-light-sources

Choosing Light Sources for AAS Measurements

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Atomic Absorption Spectroscopy: Sample Atomization

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atomic-emission-spectroscopy-instrumentation

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key terms and concepts

Learn the main parts of an atomic absorption spectrophotometer, including the lamp, atomizer, chopper, monochromator, and detector, in clear high school terms.

Atomic Absorption Spectroscopy: Key Parts | JoVE K12

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Atomic Absorption Spectroscopy: Key Parts

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