Name: icp-aes instrument types and detection
Uploaded: 2024-12-05T18:32:15.000Z
Duration: 1 min 26 s
Channel: JoVE

플라즈마 방출 분광법은 세 가지 기본 기기 유형을 사용합니다.
순차 플라즈마 방출 분광기는 한 번에 하나의 방출 라인을 측정하는 반면, 다중 채널 및 푸리에 변환 기기는 여러 방출 라인을 동시에 측정합니다.
순차 분광계는 일반적으로 격자 모노크로메이터를 사용하며, 여기서 격자는 출구 슬릿에 다른 파장을 집중시키기 위해 회전합니다.
예를 들어, 슬루 스캔 분광계에서 모노크로메이터는 하나의 방출선에 가까운 파장으로 빠르게 회전한 다음 해당 방출선을 가로질러 작은 단계로 회전합니다.
대조적으로, 스캐닝 echelle 분광계는 조리개 플레이트 뒤에 움직이는 광전자 증배관이 있으며, echelle 격자는 한 번에 하나의 슬릿을 감지할 수 있는 광범위한 어레이로 파장을 산란시킵니다.
일부 멀티채널 기기는 격자 폴리크로메이터를 사용하여 고정 출구 슬릿 뒤에 위치한 광전자 증배관과 함께 여러 방출 라인을 동시에 측정합니다.
다른 다중 채널 기기는 동시 측정을 위해 분광기를 사용하여 2차원 전하 주입 장치 또는 전하 결합 장치를 변환기로 사용합니다.
푸리에 변환 분광기는 넓은 파장 범위를 제공하지만 다양한 제한 사항으로 인해 AES에서 널리 사용되지는 않습니다.

유도 결합 플라즈마 원자 방출 분광법: 계측

Inductively Coupled Plasma Atomic Emission Spectroscopy: Instrumentation

유도 결합 플라즈마(ICP)는 시료의 다양한 원소를 감지하고 분석하는 기술인 원자 방출 분광법(AES)에 사용되는 일반적인 플라즈마 소스입니다. 이 방법을 유도 결합 플라즈마 원자 방출 분광법(ICP-AES)이라고도 합니다.

유도 결합 플라즈마 원자 방출 분광법(ICP-AES) 장비에는 순차, 동시 다중 채널 및 푸리에 변환 장비의 세 가지 주요 유형이 있으며 후자는 덜 일반적으로 사용됩니다. 순차 ICP-AES는 각 요소를 개별적으로 분석합니다. 여기서 기기는 한 요소의 라인에서 다른 요소의 라인으로 이동하도록 프로그래밍되어 있으며 라인 강도를 만족스럽게 측정하기 위해 각 요소에서 몇 초씩 일시 중지합니다. 반면, 다중 채널 장비는 여러 요소에 대한 방출선 강도를 동시에 또는 거의 측정하도록 설계되었습니다. 순차 장비는 더 간단하지만 더 많은 시간과 샘플 소비가 필요하므로 장기적으로 비용이 더 많이 듭니다.

순차 및 다중 채널 방출 분광계는 기존 격자 분광계 또는 에셸 분광기를 사용할 수 있습니다. 순차 장비에 자주 사용되는 격자 단색 장치는 밀리미터당 2400 또는 3600개의 홈이 있는 홀로그램 격자를 사용합니다. 격자는 디지털로 제어되는 스테퍼 모터로 회전하여 다양한 파장을 출구 슬릿에 순차적으로 정확하게 집중시킵니다. 슬루 스캔 분광계는 관심 라인 근처의 파장을 매우 빠르게 스캔한 후 작은 단계로 라인을 가로질러 스캔하는 속도를 늦추는 순차 기기입니다. 이 방법은 유용하지 않은 파장 영역에서 소요되는 시간을 최소화합니다.

반면에 에셸 분광기는 스캐닝 장비 또는 동시 다중 채널 분광기로 작동할 수 있습니다. 동시 다중 채널 장비에는 다생화장치 또는 분광기가 통합되어 있습니다. 다생화장치에는 감지를 위한 일련의 광전자 증배관이 포함되어 있지만 분광기는 2차원 전하 주입 장치(CID) 또는 전하 결합 장치(CCD)를 변환기로 사용합니다. 일부 다중 채널 방출 분광계에서 광전자 증배관은 격자 다색화기의 초점 곡선을 따라 고정 슬릿 뒤에 위치합니다.

AES에서 널리 사용되지는 않지만 푸리에 변환 분광계는 넓은 파장 범위, 속도, 고해상도, 매우 정확한 파장 측정, 넓은 동적 범위, 소형 크기 및 대규모 광학 처리량과 같은 이점을 제공합니다. 전반적으로 AES 장비는 순차 스캐닝부터 동시 다중 채널 감지 및 푸리에 변환 분석에 이르기까지 다양한 기능을 제공하므로 연구원과 분석가는 특정 분석 요구 사항에 가장 적합한 접근 방식을 선택할 수 있습니다.

유도 결합 플라즈마 (ICP)는 원자 방출 분광법 (AES)에 사용되는 일반적인 플라즈마 소스로, 다양한 플라즈마를 감지하고 분석하는 기술입니다.

inductively-coupled-plasma-atomic-emission-spectroscopy

Education

교육

JoVE Core

Analytical Chemistry

분석 화학

Unit 1

제1단원

Atomic Spectroscopy

원자 분광법

KEY TERMS AND CONCEPTS

주요 용어 및 개념

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 part of the instrument family. Each type handles wavelengths and element signals in a different way.

Sequential ICP-AES measures elements one at a time. The instrument moves from one element line to another and pauses for a few seconds at each point so it can measure line intensity well. These instruments are simpler, but they take more time and use more sample, so they can cost more over time.

Multichannel instruments measure emission lines for several elements at the same time, or nearly at the same time. Sequential and multichannel emission spectrometers can use either a classical grating spectrometer or an echelle spectrometer. In many sequential instruments, a grating monochromator uses a holographic grating with 2400 or 3600 grooves per millimeter, and a digitally controlled stepper motor rotates the grating to send different wavelengths to the exit slit.

Some sequential systems are slew-scan spectrometers. They move quickly to a wavelength near the line of interest and then slow down to scan across the line in small steps. This reduces time spent in wavelength regions that do not help the measurement.

An echelle spectrometer can work as a scanning instrument or as a simultaneous multichannel spectrometer. Simultaneous multichannel instruments may use a polychromator or a spectrograph. Polychromators use a series of photomultiplier tubes, while spectrographs use two-dimensional charge-injection devices, or CIDs, and charge-coupled devices, or CCDs, as transducers.

In some multichannel emission spectrometers, photomultipliers sit behind fixed slits along the focal curve of a grating polychromator. Fourier transform spectrometers are not widely used in AES, but they offer wide wavelength coverage, speed, high resolution, accurate wavelength measurements, a large dynamic range, compact size, and high optical throughput. These instrument choices let analysts match the system to the needs of a specific sample and measurement.

ICP-AES Instrument Types and Detection

atomic spectroscopy: absorption, emission, and fluorescence

atomic-spectroscopy-absorption-emission-and-fluorescence

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...

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, 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 ICP-AES instruments work, including sequential, multichannel, and Fourier transform designs, plus the detectors and spectrometers used to measure elements.

ICP-AES Instrument Types and Detection | JoVE K12

analytical chemistry

JoVE Core Analytical Chemistry simplifies complex chemical principles by breaking them down into clear, engaging animations, making topics from SI Units to NMR spectroscopy more accessible and straightforward. Additionally, the scientist-in-action videos highlight the application of these concepts in real-world research conducted in laboratories globally.

ICP-AES Instrument Types and Detection

Description

Transcript