Name: how gc-ms separates and identifies compounds
Uploaded: 2025-05-22T09:05:43.000Z
Duration: 1 min 14 s
Channel: JoVE

기체 크로마토그래피-질량 분석법(GC-MS)은 기체 크로마토그래피와 질량 분석법을 단일 기기에 결합하여 화합물 혼합물을 분석합니다.
가스 크로마토그래프는 화합물을 분리하는 데 사용되며 질량 분석기는 각 화합물의 질량을 분석하는 데 사용됩니다.
크로마토그래프 설정은 오븐에 들어 있는 길고 좁은 모세관 컬럼으로 구성됩니다. 고정상은 컬럼의 내부 표면에 코팅된 극성이 낮고 점도가 높은 고비점 실리콘 기반 재료입니다.
분석물은 크로마토그래프의 컬럼 주입구에서 주입되며, 여기서 불활성 캐리어 가스(이동상)가 이를 질량분석기로 운반합니다.
분석물의 화합물은 끓는점의 차이와 고정상에 대한 친화력의 차이 때문에 서로 다른 속도로 컬럼을 통해 이동합니다.
따라서 화합물은 서로 다른 시간 간격으로 컬럼의 다른 쪽 끝에 도달하며, 여기서 부착된 질량 분석기는 각 화합물의 질량 신호를 개별적으로 분석합니다.

가스 크로마토그래피-질량 분석법(gc-ms)

Gas Chromatography&ndash;Mass Spectrometry (GC&ndash;MS)

가스 크로마토그래피-질량 분석법(GC-MS)은 화합물 혼합물을 분석하기 위해 가스 크로마토그래피와 질량 분석법의 분석 기술을 단일 장비에 결합한 것입니다. 가스 크로마토그래프는 혼합물의 화합물을 분리하고, 질량 분석기는 각 화합물을 개별적으로 분석하여 분자 질량과 분자 구조를 결정합니다.

가스 크로마토그래프는 내벽이 폴리실록산으로 코팅된 길고 좁은 모세관 컬럼으로 구성됩니다. 코팅 물질은 끓는점이 높고 점도가 낮으며 극성이 낮은 특성을 가지며 크로마토그래피의 고정상 역할을 합니다. 분석물은 컬럼의 한쪽 끝으로 주입되고 불활성 기체 흐름을 이동상으로 사용하여 컬럼을 통해 플러시됩니다. 각 화합물의 끓는점과 고정상과의 상호 작용에 따라 컬럼을 통과하는 이동 속도가 결정됩니다. 결과적으로, 혼합물의 각 화합물은 서로 다른 시간에 컬럼의 다른 쪽 끝에 도달합니다. 결국 컬럼 끝에 연결된 질량분석기는 각 화합물을 개별적으로 분석한다.

가스 크로마토그래피-질량 분석법(GC-MS)

가스 크로마토 그래피-질량 분석법 (GC-MS)은 가스 크로마토 그래피와 질량 분석법의 분석 기술을 결합한 것입니다.

Education

교육

JoVE Core

Analytical Chemistry

분석 화학

Unit 1

제1단원

Principles of Mass Spectrometry

질량 분석법의 원리

KEY TERMS AND CONCEPTS

주요 용어 및 개념

how gc-ms separates and identifies compounds

Gas chromatography-mass spectrometry (GC-MS) separates compounds in a mixture and then identifies them. A gas chromatograph first splits the mixture into its parts. A mass spectrometer then analyzes each part on its own to determine molecular masses and molecular structures.

The gas chromatograph uses a long, narrow capillary column. The inner wall of the column has a polysiloxane coating. This coating serves as the stationary phase. It has a high boiling point, low viscosity, and low polarity.

The analyte is injected into one end of the column. An inert gas carries it through the column as the mobile phase. Each compound moves at a different speed because of its boiling point and its interaction with the stationary phase. As a result, the compounds reach the end of the column at different times.

When each compound leaves the column, it enters the mass spectrometer. The mass spectrometer then analyzes that compound separately. This step reveals the molecular mass and gives information about molecular structure.

How GC-MS Separates and Identifies Compounds

how-gc-ms-separates-and-identifies-compounds

mass spectrometry: overview

Mass Spectrometry and Molecular Identity

Mass spectrometry helps identify a compound by measuring its molecular mass and molecular formula. It does this by turning the analyte molecule into ions and then comparing ion abundance with mass-to-charge ratio. One common ionization method is electron ionization, or EI. In EI, high-energy electron beams strike analyte molecules in the gas phase. The beam removes an electron and leaves a molecular ion behind. A molecular ion is a radical cation, so it has a positive charge and an unpaired...

mass spectrometry: isotope effect

Isotope Peaks in Mass Spectra

Isotope peaks in mass spectra show how natural isotope mixtures change the signal of a molecule. Most elements occur as a mix of isotopes, which are atoms of the same element with different numbers of neutrons. Because isotopes have different masses, the same fragment can appear at more than one position in a spectrum. The mass of a molecule depends on which isotopes are present in its atoms. The size of each isotope peak also depends on how common those isotopes are in nature. Carbon is a...

mass spectrometry: molecular fragmentation overview

mass-spectrometry-molecular-fragmentation-overview

Mass Spectrometry Fragmentation Patterns

Mass spectrometry fragmentation patterns show how a molecular ion breaks apart after ionization. When a molecule loses an electron inside the mass spectrometer, its structure becomes unstable. The ion then fragments at bonds that often produce the most stable pieces. One common pattern is cleavage of a single bond in the molecular ion. This break forms a radical and a cation. The bond can split in more than one way, but the favored path is the one that gives the more stable carbocation rather...

mass spectrometers

How Mass Spectrometers Sort Ions

A mass spectrometer sorts charged ions by their mass-to-charge ratio and records their relative abundance. It turns vaporized analyte molecules into ions, separates them, and then measures the signal from each type of ion. The process begins in the ionization chamber. The analyte is in the gas phase inside a vacuum, and it is struck by high-energy electrons. The electrons have about 70 eV of energy, which is enough to remove an electron from the analyte and form a molecular ion. After...

mass spectrum

Reading Peaks in a Mass Spectrum

A mass spectrum shows the charged fragments in an analyte as peaks plotted by mass-to-charge ratio, or m/z. The x-axis gives the mass of each charged fragment divided by the number of charges it carries. The y-axis shows the relative abundance of each charged species based on the signal intensity recorded at the detector. The tallest peak is called the base peak. It is assigned an abundance of 100%, and the other peaks are scaled against it. The peak from the molecular ion is called the parent...

mass spectrum: interpretation

Decoding Molecular Ions in Mass Spectra

Mass spectra help scientists identify an unknown compound by finding the molecular ion peak. The molecular ion peak shows the mass of the intact molecule, but it is often weak or missing because high-energy electron beams cause strong fragmentation. When that happens, a soft-energy electron beam can be used to scan the spectrum and improve the molecular ion signal. Other ionization methods can also give a stronger molecular ion peak. Chemical ionization, field ionization, and desorption...

mass analyzers: overview

Mass Analyzers and Ion Separation

Mass analyzers separate ions by their mass-to-charge ratio, or m/z, in a mass spectrometer. After a sample is vaporized in the ionization chamber, it is hit with a high-energy electron beam. This creates a radical cation and also produces neutral molecules, radicals, and cations. Negatively charged accelerator plates then push the cations into the mass analyzer, where they are sent on to the detector. Several mass analyzer designs are commonly used. These include magnetic sector,...

mass analyzers: common types

Quadrupole, TOF, and Ion Trap Analyzers

Quadrupole, time-of-flight, and ion trap mass analyzers each separate ions in a different way. They are common tools in mass spectrometry and help sort ions by their mass-to-charge ratio, or m/z. A quadrupole mass analyzer uses four cylindrical metal rods arranged in a diamond shape. The rods carry a direct current, or DC, voltage and a radio-frequency AC voltage. Ion motion depends on the field strength, so only ions with a certain m/z resonate and reach the detector at that setting. This...

high-resolution mass spectrometry (hrms)

Mass Accuracy in HRMS Analysis

High-resolution mass spectrometry separates ions by very small differences in mass. This matters because atomic masses are not always exact whole numbers, even though they are often rounded for simple calculations. Atomic mass is usually estimated by adding the masses of protons and neutrons. In reality, the proton and neutron do not have exactly the same mass. That creates small differences when atomic masses are compared to the simplest hydrogen atom. Helium, for example, is made of 2...

mass spectrometry: complex analysis

Hyphenated Mass Spectrometry Methods

Mass spectrometry can be paired with separation methods to study complex mixtures. This combination is called a hyphenated method. It helps when a pure mass spectrum is too hard to read because a mixture causes too much fragmentation and too many overlapping signals. GC-MS is one common hyphenated method. GC stands for gas chromatography, which separates volatile, thermally stable compounds in narrow capillary columns before they enter the mass spectrometer. This approach is widely used in...

tandem mass spectrometry

MS/MS Scan Modes and Fragment Ions

Tandem mass spectrometry uses two or more mass analyzers in series to improve selectivity and lower chemical noise during analyte detection. A set of analyzers separated by an interaction cell lets the instrument break ions apart and study the fragment ions that form. Fragmentation happens in the interaction cell and can be caused in several ways. Collision-induced dissociation, or CID, uses inert gases such as nitrogen, argon, or helium. Other methods include surface-induced dissociation...

gas chromatography&ndash;mass spectrometry (gc&ndash;ms)

Gas chromatography-mass spectrometry (GC-MS) separates compounds in a mixture and then identifies them. A gas chromatograph first splits the mixture into its parts. A mass spectrometer then analyzes each part on its own to determine molecular masses and molecular structures. The gas chromatograph uses a long, narrow capillary column. The inner wall of the column has a polysiloxane coating. This coating serves as the stationary phase. It has a high boiling point, low viscosity, and low polarity.

inductively coupled plasma&#8211;mass spectrometry (icp&#8211;ms): overview

inductively-coupled-plasmamass-spectrometry-icpms-overview

ICP-MS Sample Ionization and Detection

ICP-MS uses an inductively coupled plasma torch to turn samples into ions for mass analysis. Solid samples are first dissolved and volatilized before they enter the hot argon plasma. Solution samples are nebulized, which means they are converted into a fine spray, and then passed through the same plasma. Inside the plasma, the analytes break apart. Their atoms become positively charged ions, along with some molecular species. These positive ions are sent to the mass spectrometer, where they...

inductively coupled plasma-mass spectrometry (icp-ms): interferences

inductively-coupled-plasma-mass-spectrometry-icp-ms-interferences

ICP-MS Signal Interference Sources and Fixes

Inductively coupled plasma-mass spectrometry (ICP-MS) is a sensitive method for elemental analysis, but its spectra can be affected by interferences. These interferences can make the mass signal less accurate, even when the instrument is working well. Spectroscopic interferences happen when ions in the plasma have the same mass-to-charge ratio, or m/z, as the analyte ion. This group includes isobaric interferences, polyatomic ion interferences, and refractory oxide ion interferences. Isobaric...

key terms and concepts

Learn how GC-MS uses gas chromatography to separate a mixture and mass spectrometry to identify each compound by mass and structure.

How GC-MS Separates and Identifies Compounds | 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.

How GC-MS Separates and Identifies Compounds

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