Name: element analysis with atomic light spectra
Uploaded: 2024-12-05T18:32:13.000Z
Duration: 1 min 23 s
Channel: JoVE

K12 Standards

Pennsylvania State Academic Standards

9-12

Earth and Space Science

Space Systems

3.3.9-12.B

atomic-spectroscopy-absorption-emission-and-fluorescence

Atomic Spectroscopy: Absorption, Emission, and Fluorescence

原子分光法は、定性的および定量的元素分析のための分析ツールです。
主な種類には、原子吸光分光法(AAS)、原子発光分光法(AES)、原子蛍光分光法(AFS)などがあります。
3つの方法はすべて、液体サンプルを気相原子に分解する重要なステップである噴霧から始まります。
AASでは、さまざまな電磁放射を照射された高温のガス状サンプルが特定の波長の光を吸収し、原子内の電子遷移を高エネルギー軌道に引き起こします。
各波長で透過する光の量は、検出器によって測定されます。 
AESでは、基底状態の気体原子に熱または放電が入力されると、電子励起が発生します。
これらの高エネルギー原子は、エネルギー差に一致する光子を放出して、すぐに基底状態に戻ります。
AFSでは、基底状態の気体原子に特徴的な波長で照射することで、特定の原子を励起状態に促進します。
原子が存在する場合、それは蛍光を発し、これはレーザービームに対して直角に配置された検出器によって測定されます。

原子分光法: 吸収、発光、蛍光

原子分光法は、定性的にも定量的にも元素分析に不可欠なツールです。大きく分けて、光学分光法、質量分光法、X 線分光法があります。光学分光法は、原子吸光分光法 (AAS)、原子発光分光法 (AES)、原子蛍光分光法 (AFS) です。3 つの方法のすべてで最初のステップは原子化です。原子化では、固体、液体、または溶液相のサンプルが気相の原子とイオンに変換されます。

AAS では、ガスサンプルが電磁放射と相互作用し、基底状態の原子の電子を励起状態にするのとまったく同じエネルギーを持つ光子を吸収します。たとえば、Na 原子の不対 3s 電子は、それぞれ 285 nm、330 nm、または 590 nm の放射線を吸収すると、3p、4p、または 5p 軌道に昇格します。特定の波長の透過光の減少は検出器によって測定され、吸光度または透過率スペクトルで視覚化されます。

AES では、基底状態の気相原子は熱または放電エネルギーによって電子的に励起されます。これらの短寿命で高エネルギーの励起気相原子は基底状態に戻り、エネルギーギャップに対応する光子を放出します。放出された光の強度が検出され、サンプルの指紋となる電気信号に変換されます。たとえば、励起された Na 原子が 3p、4p、および 5p 軌道から 3s 軌道に戻る電子遷移により、それぞれ 590 nm、330 nm、および 285 nm 付近で放出されます。放出された放射線が測定され、スペクトルに処理されます。

AFS では、基底状態の気相原子に特性波長が照射され、電子励起状態になります。無放射遷移が発生しない場合、励起状態の原子は吸収したエネルギーに対応する正確な波長で蛍光を発して基底状態に緩和します。検出器は通常、光源ビームに対して直角に配置され、蛍光発光のみが検出器に到達します。

分子スペクトルとは異なり、原子スペクトルは、分子スペクトルのピークの広がりにつながるさまざまな回転および振動エネルギー状態がないため、鋭い線を持ちます。

原子分光法は、定性的にも定量的にも元素分析に不可欠なツールです。それは大きく分けることができます 光分光法、...

Education

JoVE Core

Analytical Chemistry

分析化学

Unit 1

ユニット1

Atomic Spectroscopy

原子分光法

KEY TERMS AND CONCEPTS

主要用語と概念

element analysis with atomic light spectra

Atomic spectroscopy is used to identify and measure elements by their light signals. It supports both qualitative analysis, which tells what is present, and quantitative analysis, which tells how much is present. The optical methods in this group are atomic absorption spectroscopy, atomic emission spectroscopy, and atomic fluorescence spectroscopy.

These methods begin with atomization. In this step, a solid, liquid, or solution sample is changed into gas-phase atoms and ions. Once the sample is in the gas phase, each method uses light or energy in a different way to study the atoms.

In atomic absorption spectroscopy, gas-phase atoms absorb electromagnetic radiation with the exact energy needed to move electrons to higher levels. For example, the 3s electron of sodium can be promoted to the 3p, 4p, or 5p orbital by light of 285 nm, 330 nm, or 590 nm. The detector measures the drop in transmitted light at selected wavelengths and shows it as an absorbance or transmittance spectrum.

In atomic emission spectroscopy, ground-state gas-phase atoms are excited by heat or electrical discharge energy. These excited atoms quickly return to the ground state and release photons that match the energy gap. The emitted light is detected and converted to an electrical signal that gives a fingerprint of the sample. For sodium, transitions from the 3p, 4p, and 5p orbitals back to 3s produce emissions around 590 nm, 330 nm, and 285 nm.

Atomic fluorescence spectroscopy also starts with ground-state gas-phase atoms. They are irradiated with a characteristic wavelength and moved to an excited state. If radiationless transition does not occur, the atoms return to the ground state by fluorescing at the same wavelength they absorbed. The detector is usually placed at a right angle to the source beam so it measures mostly the fluorescence signal.

Atomic spectra are different from molecular spectra because they have sharp lines. Molecules have rotational and vibrational energy states that can broaden peaks, but atoms do not show that same type of broadening. That is why atomic spectra often appear as narrow, distinct signals.

Element Analysis with Atomic Light Spectra

element-analysis-with-atomic-light-spectra

atomic spectroscopy: absorption, emission, and fluorescence

Atomic spectroscopy is used to identify and measure elements by their light signals. It supports both qualitative analysis, which tells what is present, and quantitative analysis, which tells how much is present. The optical methods in this group are atomic absorption spectroscopy, atomic emission spectroscopy, and atomic fluorescence spectroscopy. These methods begin with atomization. In this step, a solid, liquid, or solution sample is changed into gas-phase atoms and ions. Once the sample...

atomic spectroscopy: effects of temperature

atomic-spectroscopy-effects-of-temperature

How Heat Changes Atomic Spectra

Heat changes atomic spectra by affecting atomization, excitation, ionization, and line shape. In atomic spectroscopy, atomization means converting a sample into gas-phase atoms and ions. The flame temperature needed for this step changes how efficiently the method works and shifts the balance between excited and ground-state atoms. At thermal equilibrium, the relative numbers of excited and ground-state atoms can be estimated with the Maxwell-Boltzmann distribution. A small temperature rise...

atomic absorption spectroscopy: overview

Atomic Absorption Spectroscopy for Trace Metals

Atomic absorption spectroscopy (AAS) measures trace metals by tracking how atoms absorb electromagnetic radiation (EMR). The absorbed light makes atoms move to a higher-energy orbit. In AAS, the key step is atomization, which converts the sample into gas-phase atoms. A flame or a furnace is typically used for this step. Inside the flame, some atoms become thermally excited. Most stay in the ground state, which is the lowest-energy state. These ground-state gas-phase atoms absorb EMR only when...

atomic absorption spectroscopy: instrumentation

atomic-absorption-spectroscopy-instrumentation

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...

atomic absorption spectroscopy: radiation and light sources

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

Choosing Light Sources for AAS Measurements

Atomic absorption spectroscopy (AAS) uses a light source that emits a very narrow range of wavelengths. This is needed because the source must match the absorption behavior of the analyte atom. The choice of source also depends on giving a precise, intense emission at the right wavelength for accurate detection. Two common line sources in AAS are hollow-cathode lamps (HCLs) and electrodeless-discharge lamps (EDLs). These lamps are selected based on the element being analyzed and the level of...

atomic absorption spectroscopy: atomization methods

atomic-absorption-spectroscopy-atomization-methods

Atomic Absorption Spectroscopy: Sample Atomization

Atomic absorption spectroscopy uses sample atomization to turn a liquid specimen into free atoms for analysis. The two main approaches are flame atomization and electrothermal atomization. Both methods prepare the sample so its atoms can be measured by the instrument. Flame atomization uses a nebulizer and spray chamber to mix the sample with a fuel-oxidant mixture. This creates a fine aerosol mist that enters the burner. The fuel and oxidant are usually close to a stoichiometric ratio, but a...

atomic absorption spectroscopy: interference

atomic-absorption-spectroscopy-interference

Correcting Errors in Atomic Absorption Spectroscopy

Atomic absorption spectroscopy interference can create systematic error by making the analytical signal or the background look stronger or weaker than it should be. In atomic absorption measurements, these errors are usually grouped as spectral interference, chemical interference, and physical interference. Spectral interference happens when signals from other elements or molecules overlap with the analyte signal, the substance being measured. This overlap can falsely raise or hide the analyte...

atomic absorption spectroscopy: lab

AAS Sample Prep and Calibration

Atomic absorption spectroscopy (AAS) depends on careful sample preparation and calibration. Samples must be turned into clear solutions before measurement. That often means extra treatment to dissolve materials such as soils, animal tissues, and minerals. Common sample prep methods include hot mineral acids, wet ashing, combustion in closed containers, high-temperature ashing, and fusion with reagents. These steps help make the sample suitable for AAS analysis. Solutions that contain organic...

atomic emission spectroscopy: overview

Atomic Emission Spectroscopy for Element Analysis

Atomic emission spectroscopy is used to identify the elements in a sample by measuring the light they emit. Atoms are first excited to higher energy levels by thermal energy from hot sources such as plasma, arcs, or sparks. When they fall back to lower energy levels, they give off light at specific wavelengths. Each element produces its own set of lines, so the emission spectrum can show both what is present and how much is there. AES instruments are similar to atomic absorption spectrometers,...

atomic emission spectroscopy: instrumentation

atomic-emission-spectroscopy-instrumentation

AES Sample Handling and Detection

Atomic emission spectrometry (AES) uses sample handling, atomization, and detection parts to measure emitted light from atoms and ions. The sample must first be changed into a gas-phase form so it can produce a measurable signal. AES uses two main atomizer types. Continuous atomizers, such as flames and plasmas, feed the sample in a steady stream. Discrete atomizers add one sample at a time with syringes or autosamplers. The electrothermal atomizer is the most common discrete type. Many...

atomic emission spectroscopy: interference

atomic-emission-spectroscopy-interference

Reducing Interference in AES Signals

Atomic emission spectroscopy (AES) can produce interfering signals when atoms and molecules in a flame or plasma emit overlapping light. High-temperature atomizers excite many species at once, including oxides, hydroxides, and flame combustion products. These extra emissions can make the analyte signal harder to read. Spectral interference happens when emission lines or bands overlap. One way to reduce it is to improve instrument resolution. Another is to choose a different emission line for...

inductively coupled plasma atomic emission spectroscopy: principle

inductively-coupled-plasma-atomic-emission-spectroscopy-principle

ICP-AES Torch and Sample Analysis

Inductively coupled plasma atomic emission spectroscopy uses a plasma torch to analyze elements in a sample. This method is also called inductively coupled plasma optical emission spectroscopy, or ICP-OES. It is widely used because the plasma creates a strong environment for elemental analysis. The ICP source, or torch, contains three concentric quartz tubes. Argon gas flows through the tubes. A spark from a Tesla coil starts the ionization of argon and creates a high-temperature plasma. The...

inductively coupled plasma atomic emission spectroscopy: instrumentation

inductively-coupled-plasma-atomic-emission-spectroscopy

ICP-AES Instrument Types and Detection

Inductively coupled plasma atomic emission spectroscopy, or ICP-AES, uses an inductively coupled plasma to detect and analyze elements in a sample. The method measures the light given off by atoms, which helps identify and compare different elements. It is a common approach in atomic emission spectroscopy. ICP-AES instruments are built in three main forms: sequential, simultaneous multichannel, and Fourier transform instruments. Fourier transform designs are less commonly used, but they are...

atomic emission spectroscopy: lab

Plasma Sources in Atomic Emission Spectroscopy

Atomic emission spectroscopy uses plasma sources to identify elements by their light. The method creates abundant spectra with characteristic emission lines. Inductively coupled plasma, or ICP, is especially useful because it gives strong quantitative data. It works well under stable conditions, with low noise, low background, and few interferences. Newer air-operated microwave sources are also being studied. These sources may be more cost-effective than conventional ICP systems. Atomic...

atomic fluorescence spectroscopy

Measuring Elements by Atomic Fluorescence

Atomic fluorescence spectroscopy measures elements by detecting the light atoms give off after they are excited by electromagnetic radiation. The atoms are first placed in a flame, furnace, or plasma. They absorb energy, become excited, and then release that energy as they return to their original state. The emitted light is called fluorescence. The fluorescence is observed at a right angle to the incoming beam. This setup helps separate the emitted light from the light used to excite the...

flame photometry: overview

Flame Emission Spectrometry Basics

Flame emission spectrometry uses a flame to excite elements in a sample so their light can be measured. It is also called flame photometry. The method can be used for both qualitative and quantitative analysis of elements. The idea became established in the early 1860s when Kirchhoff and Bunsen showed that specific elements give off characteristic radiation in a flame. The first instrument for this purpose measured sodium in plant ash with a Bunsen flame. A major problem was how to add the...

flame photometry: lab

Flame Photometry and Metal Detection

Flame photometry is a method for detecting metals by measuring the light they emit in a flame. A solution such as potassium chloride is aspirated into the flame. The solvent evaporates first. The remaining salt becomes dehydrated and then dissociates into free gaseous atoms in the ground state. Some of these atoms absorb energy from the flame and move to an excited state. When they return to the ground state, they emit photons at characteristic wavelengths. These emissions are very narrow...

key terms and concepts

Learn how atomic absorption, emission, and fluorescence spectroscopy use light to identify elements, measure signals, and produce sharp atomic spectra.

Element Analysis with Atomic Light Spectra | JoVE K12

JoVE Core 分析化学 は、複雑な化学原理をアニメーションで視覚化することで、SI 単位から NMR 分光法を含むトピックをよりわかりやすくします。実験を撮影した実写動画では、これらの概念が世界中の研究所でどのように応用されているかを取り上げています。

analytical chemistry

3.3.9-12.C

Louisiana Student Standards for Science

High School

Earth Science

Earth’s Place In The Universe

HS-ESS1-2

Chemistry

motion-and-stability-forces-and-interactions

Motion And Stability: Forces And Interactions

HS-PS2-6

Arizona Science Standards

Physical Science

HS+C.P1

HS+C.P1U1.2

Texas Essential Knowledge and Skills

Physics

PHYS.8

PHYS.8.F

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

waves-and-their-applications-in-technologies-for-information-transfer

Waves and Their Applications in Technologies for Information Transfer

C-PS4-4

the-principle-of-superposition-and-the-gravitational-field

The Principle of Superposition and the Gravitational Field

The principle of superposition applies to gravitational forces of objects that are sufficiently far apart. It states that the net gravitational force on a ...

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Escape Velocity

The escape velocity of an object is defined as the minimum initial velocity that it requires to escape the surface of another object to which it is ...

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Circular Orbits and Critical Velocity for Satellites

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Kepler's Second Law of Planetary Motion

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Kepler's Third Law of Planetary Motion

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Nuclear Fusion

The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process ...

Nuclear Power

Controlled nuclear fission reactions are used to generate electricity. Any nuclear reactor that produces power via the fission of uranium or plutonium by ...

Nuclear Fission

Many heavier elements with smaller binding energies per nucleon can decompose into more stable elements that have intermediate mass numbers and larger ...

Nuclear Transmutation

Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with ...

Atomic Structure

All matter is composed of atoms, the smallest individual units of elements. Each atom is made up of three subatomic particles: protons, neutrons, and ...

Radioactivity and Nuclear Equations

Nuclear chemistry is the study of reactions that involve changes in nuclear structure. The nucleus of an atom is composed of protons and, except for ...

Nuclear Stability

Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10&#8722;15 meters, a nucleus is ...

Students who demonstrate understanding can develop a model based on evidence to illustrate the life span of the sun and the role of nuclear fusion in the sun's core to release energy in the form of radiation.  Clarification Statement: Emphasis is on the energy transfer mechanisms that allow energy from nuclear fusion in the sun's core to reach Earth.  Examples of evidence for the model include observations of the masses and lifetimes of other stars, as well as the ways that the sun's radiation varies due to sudden solar flares ("space weather"), the 11-year sunspot cycle, and non-cyclic variations over centuries.  Assessment Boundary: Assessment does not include details of the atomic and sub-atomic processes involved with the sun's nuclear fusion.

3.3.9-12.A

Emission Spectra

When solids, liquids, or condensed gases are heated sufficiently, they radiate some of the excess energy as light. Photons produced in this manner have a ...

Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, ...

Detection of Black Holes

Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
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Space-Time Curvature and the General Theory of Relativity

In 1905, Albert Einstein published his special theory of relativity. According to this theory, no matter in the universe can attain a speed greater than ...

Schwarzschild Radius and Event Horizon

No object with a finite mass can travel faster than the speed of light in a vacuum. This fact has an interesting consequence in the domain of extremely ...

The Wave Nature of Light

The nature of light has been a subject of inquiry since antiquity. In the seventeenth century, Isaac Newton performed experiments with lenses and prisms ...

Nuclear Binding Energy

The difference between the calculated and experimentally measured masses is known as the mass defect of the atom. In the case of helium-4, the mass defect ...

Metal Flame Emission

Metal Flame Emission
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molecular-spectroscopy-absorption-and-emission

Molecular Spectroscopy: Absorption and Emission

Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational ...

Atomic Emission Spectroscopy: Instrumentation

The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase ...

Atomic Absorption Spectroscopy: Radiation and Light Sources

Atomic absorption spectroscopy (AAS) relies on the Beer-Lambert law, which requires that the radiation source emits a narrow range of wavelengths to match ...

Students who demonstrate understanding can construct an explanation of the Big Bang theory based on astronomical evidence of light spectra, motion of distant galaxies, and composition of matter in the universe.  Clarification Statement: Emphasis is on the astronomical evidence of the red shift of light from galaxies as an indication that the universe is currently expanding, the cosmic microwave background as the remnant radiation from the Big Bang, and the observed composition of ordinary matter of the universe, primarily found in stars and interstellar gases (from the spectra of electromagnetic radiation from stars), which matches that predicted by the Big Bang theory (3/4 hydrogen and 1/4 helium).  Assessment Boundary:

Spectrophotometry: Introduction

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Atomic Emission Spectroscopy: Overview

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ultraviolet-and-visible-uvvis-spectroscopy-overview

Ultraviolet and Visible (UV&ndash;Vis) Spectroscopy: Overview

Ultraviolet&#8211;visible (UV&#8211;visible or UV&#8211;Vis) spectroscopy is an analytical technique that investigates the interaction between matter and ...

Atomic Emission Spectroscopy: Lab

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Flame Photometry: Overview

Flame photometry, also known as flame emission spectrometry, is a technique used for the qualitative and quantitative analysis of elements present in a ...

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Students who demonstrate understanding can communicate scientific ideas about the way stars, over their life cycle, produce elements.  Clarification Statement: Emphasis is on the way nucleosynthesis, and therefore the different elements created, varies as a function of the mass of a star and the stage of its lifetime.  Assessment Boundary: Details of the many different nucleosynthesis pathways for stars of differing masses are not assessed.

Tidal Forces

The origin of Earth&#39;s ocean tides has been a subject of continuous investigation for over 2000 years. However, the work of Newton is considered to be ...

Students who demonstrate understanding can use mathematical or computational representations to predict the motion of orbiting objects in the solar system.  Clarification Statement: Emphasis is on Newtonian gravitational laws governing orbital motions, which apply to human-made satellites as well as planets and moons.  Assessment Boundary: Mathematical representations for the gravitational attraction of bodies and Kepler's Laws of orbital motions should not deal with more than two bodies, nor involve calculus.

3.3.9-12.D

Element Analysis with Atomic Light Spectra

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