Chromatography

70問 • 6ヶ月前

Liane

通報

問題一覧

What is the principle behind partition chromatography in liquid chromatography?

Partitioning between two immiscible phases

Which stationary phase is used in adsorption chromatography?

Solid adsorbent (e.g., alumina)

What is the main method for elution in ion exchange chromatography?

Changing pH or salt concentration

Which type of liquid chromatography separates analytes based on molecular size?

Size-exclusion chromatography

What type of stationary phase does a cation exchange column use?

Stationary phase has negatively charged groups

Which component is separated by anion exchange chromatography?

Anions, DNA, RNA, and certain proteins

What is a key characteristic of High-Performance Liquid Chromatography (HPLC) compared to regular LC?

Uses high pressure to achieve faster, more precise separations

Which elution method is used in affinity chromatography?

Changing buffer or adding a competitive ligand

Which application would best suit size-exclusion chromatography?

Separation of proteins and polymers by size

In partition chromatography, what defines the analyte's interaction with the stationary phase?

Partitioning between the two phases

Which type of chromatography separates water-soluble biomolecules using an aqueous mobile phase?

Gel Filtration Chromatography

In size-exclusion chromatography, why do larger molecules elute first?

They are excluded from entering the pores of the beads.

What is the main purpose of the detector in a liquid chromatography system?

To detect separated components as they elute from the column

Which mobile phase is suitable for gel permeation chromatography used in polymer analysis?

An organic mobile phase

What is the function of the column oven in a liquid chromatography system?

To maintain constant temperature for better reproducibility

Which detector is most commonly used in liquid chromatography due to its broad applicability, sensitivity, and compatibility with various compounds?

UV-Visible (UV-Vis) detector

What stationary phase is commonly used in reverse-phase (RP) liquid chromatography columns?

Octadecyl-bonded silica (C18)

Which type of liquid chromatography column separates analytes based on their molecular size?

Size-Exclusion Chromatography (SEC)

Which detector records absorbance across a range of wavelengths simultaneously and is useful for peak purity analysis?

Photodiode Array (PDA) detector

For the separation of enantiomers (optical isomers), which type of stationary phase would most likely be used?

Chiral selectors (e.g., cyclodextrins, proteins, cellulose derivatives)

Which stationary phase is best suited for separating charged molecules, such as amino acids, peptides, and nucleotides, on the basis of ionic interactions?

Ion-Exchange (IEX) column with sulfonic acid (cation) or quaternary amine (anion) resins

What detection principle does the Refractive Index (RI) detector use in LC?

Measures change in refractive index of the eluent

Which detector is highly sensitive and selective, and provides molecular weight and structure information in liquid chromatography?

Mass Spectrometry (MS) detector

Which type of stationary phase would be most appropriate for the separation of nonpolar compounds using nonpolar mobile phases in LC?

Normal-Phase (NP) columns with bare silica or cyano bonded silica

Which LC detector has universal applicability for non-UV absorbing compounds such as sugars, alcohols, and lipids, but generally has low sensitivity?

Refractive Index (RI) detector

Which of the following best describes the main function of gas chromatography (GC)?

To separate, identify, and quantify compounds that can be vaporized without decomposition

What is the primary difference between Gas-Liquid Chromatography (GLC) and Gas-Solid Chromatography (GSC)?

GLC uses a liquid stationary phase coated on a solid support, while GSC uses a solid adsorbent as the stationary phase.

Which type of column is most commonly used in modern GC analyses?

Long, narrow capillary columns (open tubular columns)

Why is helium often chosen as the carrier gas in GC?

Because it is inert and compatible with most detectors

What is the main limitation of Gas-Solid Chromatography (GSC) compared to GLC?

Peak tailing and limited resolution

Which injection modes are commonly used in sample injectors for GC?

Split, splitless, and on-column

In the context of carrier gases in GC, order the gases by increasing optimal linear flow rate.

N2 < He < H2

Which of the following is a typical application of GC?

Environmental analysis, Pharmaceuticals, Forensics, Food testing

What is the main advantage of open tubular (capillary) columns over packed columns in GC?

Excellent separation efficiency and sharp, symmetrical peaks

Why can hydrogen (H2) be used at higher flow rates in GC without significant loss of resolution?

Because H2 enables the fastest separations and maintains resolution even at elevated flow rates.

Which component of a gas chromatography system delivers an inert gas to carry analytes through the column?

Carrier Gas System

What is the main function of the oven in a gas chromatography system?

It houses the column and controls its temperature to optimize separation

Which type of column in gas chromatography typically has a very narrow inner diameter (0.1-0.53 mm) and lengths up to 100 m?

Open Tubular columns

Name one common material used for packed columns in gas chromatography.

Stainless steel, Glass

Which detector property allows it to identify compounds as they elute from the column?

It responds to specific properties of compounds

What is the primary function of the oven in gas chromatography?

To house the column and precisely control its temperature

Which gas chromatography detector is highly selective for halogenated and nitro group-containing compounds?

Electron Capture Detector (ECD)

What is a typical initial step of a temperature program in gas chromatography?

Starting with a low, constant temperature before ramping up

Which detector in gas chromatography is considered universal for detecting both organic and inorganic compounds?

Thermal Conductivity Detector (TCD)

Which of the following is an early sign of stationary phase degradation in a gas chromatography column?

Increased baseline noise

What is the main principle that chromatography uses to separate components in a mixture?

Differences in the rates of movement through a stationary phase carried by a mobile phase

Which of the following describes the stationary phase in chromatography?

A solid or liquid phase that stays fixed in place

Which type of chromatography typically uses a thin layer on a plate as its stationary phase and moves the mobile phase by capillary action?

Planar chromatography

What is a chromatogram?

A graphical representation showing the detector's response over time, with each peak corresponding to a different component

Which of the following is TRUE about column chromatography compared to planar chromatography?

It typically uses a packed tube or column and is suitable for high-accuracy and quantitative analysis

What serves as the stationary phase in paper chromatography?

Cellulose in filter paper

Which separation principle is the primary basis for thin layer chromatography (TLC)?

Adsorption chromatography

What is typically used as the detection method for colorless analytes in TLC?

UV light, Iodine chamber, Chemical staining reagents

Which chromatography method has higher resolution and more defined spots?

Thin Layer Chromatography (TLC)

Which feature describes the speed of separation in paper chromatography?

Slower (takes longer to develop)

Which method has a slightly higher cost due to coated plates?

Thin Layer Chromatography (TLC)

What are the three main steps involved in both paper and thin layer chromatography procedures?

Spotting, Development, Detection

For which common use is paper chromatography especially suitable?

Preliminary identification of plant pigments, amino acids, inks

Which chromatography technique is better suited for semi-quantitative analysis?

Thin Layer Chromatography (TLC)

In the development stage of chromatography, how does the solvent move through the stationary phase?

By capillary action

Which detection method for TLC allows you to observe spots directly under a UV lamp, provided the TLC plate has a fluorescent indicator such as F254?

UV light (UV Lamp) detection

In thin-layer chromatography (TLC), what does a higher Rf value indicate about the polarity of the analyte?

The analyte is less polar

After developing a TLC plate, a student stains the plate to visualize amino acids. Which chemical reagent is commonly used for this purpose?

Ninhydrin

Which detection method in TLC is noted as non-destructive and is particularly good for visualizing lipids and hydrocarbons?

Iodine vapor chamber

If a compound traveled 3.0 cm and the solvent front moved 6.0 cm in a chromatography experiment, what is the Rf value of the compound?

0.5

Which type of chromatography uses an inert gas as the mobile phase?

Gas Chromatography

What kinds of compounds are best analyzed using Liquid Chromatography?

Non-volatile, thermally sensitive compounds, Biomolecules, pharmaceuticals, food additives, polymers

Which method generally provides faster analysis for volatile compounds?

Gas Chromatography

What is a primary limitation of Gas Chromatography as compared to Liquid Chromatography?

Not suitable for non-volatile or heat-sensitive compounds

Which type of mass spectrometry interface is commonly used with Liquid Chromatography?

Soft ionization methods (e.g., ESI, APCI)

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問題一覧

What is the principle behind partition chromatography in liquid chromatography?

Partitioning between two immiscible phases

Which stationary phase is used in adsorption chromatography?

Solid adsorbent (e.g., alumina)

What is the main method for elution in ion exchange chromatography?

Changing pH or salt concentration

Which type of liquid chromatography separates analytes based on molecular size?

Size-exclusion chromatography

What type of stationary phase does a cation exchange column use?

Stationary phase has negatively charged groups

Which component is separated by anion exchange chromatography?

Anions, DNA, RNA, and certain proteins

What is a key characteristic of High-Performance Liquid Chromatography (HPLC) compared to regular LC?

Uses high pressure to achieve faster, more precise separations

Which elution method is used in affinity chromatography?

Changing buffer or adding a competitive ligand

Which application would best suit size-exclusion chromatography?

Separation of proteins and polymers by size

In partition chromatography, what defines the analyte's interaction with the stationary phase?

Partitioning between the two phases

Which type of chromatography separates water-soluble biomolecules using an aqueous mobile phase?

Gel Filtration Chromatography

In size-exclusion chromatography, why do larger molecules elute first?

They are excluded from entering the pores of the beads.

What is the main purpose of the detector in a liquid chromatography system?

To detect separated components as they elute from the column

Which mobile phase is suitable for gel permeation chromatography used in polymer analysis?

An organic mobile phase

What is the function of the column oven in a liquid chromatography system?

To maintain constant temperature for better reproducibility

Which detector is most commonly used in liquid chromatography due to its broad applicability, sensitivity, and compatibility with various compounds?

UV-Visible (UV-Vis) detector

What stationary phase is commonly used in reverse-phase (RP) liquid chromatography columns?

Octadecyl-bonded silica (C18)

Which type of liquid chromatography column separates analytes based on their molecular size?

Size-Exclusion Chromatography (SEC)

Which detector records absorbance across a range of wavelengths simultaneously and is useful for peak purity analysis?

Photodiode Array (PDA) detector

For the separation of enantiomers (optical isomers), which type of stationary phase would most likely be used?

Chiral selectors (e.g., cyclodextrins, proteins, cellulose derivatives)

Which stationary phase is best suited for separating charged molecules, such as amino acids, peptides, and nucleotides, on the basis of ionic interactions?

Ion-Exchange (IEX) column with sulfonic acid (cation) or quaternary amine (anion) resins

What detection principle does the Refractive Index (RI) detector use in LC?

Measures change in refractive index of the eluent

Which detector is highly sensitive and selective, and provides molecular weight and structure information in liquid chromatography?

Mass Spectrometry (MS) detector

Which type of stationary phase would be most appropriate for the separation of nonpolar compounds using nonpolar mobile phases in LC?

Normal-Phase (NP) columns with bare silica or cyano bonded silica

Which LC detector has universal applicability for non-UV absorbing compounds such as sugars, alcohols, and lipids, but generally has low sensitivity?

Refractive Index (RI) detector

Which of the following best describes the main function of gas chromatography (GC)?

To separate, identify, and quantify compounds that can be vaporized without decomposition

What is the primary difference between Gas-Liquid Chromatography (GLC) and Gas-Solid Chromatography (GSC)?

GLC uses a liquid stationary phase coated on a solid support, while GSC uses a solid adsorbent as the stationary phase.

Which type of column is most commonly used in modern GC analyses?

Long, narrow capillary columns (open tubular columns)

Why is helium often chosen as the carrier gas in GC?

Because it is inert and compatible with most detectors

What is the main limitation of Gas-Solid Chromatography (GSC) compared to GLC?

Peak tailing and limited resolution

Which injection modes are commonly used in sample injectors for GC?

Split, splitless, and on-column

In the context of carrier gases in GC, order the gases by increasing optimal linear flow rate.

N2 < He < H2

Which of the following is a typical application of GC?

Environmental analysis, Pharmaceuticals, Forensics, Food testing

What is the main advantage of open tubular (capillary) columns over packed columns in GC?

Excellent separation efficiency and sharp, symmetrical peaks

Why can hydrogen (H2) be used at higher flow rates in GC without significant loss of resolution?

Because H2 enables the fastest separations and maintains resolution even at elevated flow rates.

Which component of a gas chromatography system delivers an inert gas to carry analytes through the column?

Carrier Gas System

What is the main function of the oven in a gas chromatography system?

It houses the column and controls its temperature to optimize separation

Which type of column in gas chromatography typically has a very narrow inner diameter (0.1-0.53 mm) and lengths up to 100 m?

Open Tubular columns

Name one common material used for packed columns in gas chromatography.

Stainless steel, Glass

Which detector property allows it to identify compounds as they elute from the column?

It responds to specific properties of compounds

What is the primary function of the oven in gas chromatography?

To house the column and precisely control its temperature

Which gas chromatography detector is highly selective for halogenated and nitro group-containing compounds?

Electron Capture Detector (ECD)

What is a typical initial step of a temperature program in gas chromatography?

Starting with a low, constant temperature before ramping up

Which detector in gas chromatography is considered universal for detecting both organic and inorganic compounds?

Thermal Conductivity Detector (TCD)

Which of the following is an early sign of stationary phase degradation in a gas chromatography column?

Increased baseline noise

What is the main principle that chromatography uses to separate components in a mixture?

Differences in the rates of movement through a stationary phase carried by a mobile phase

Which of the following describes the stationary phase in chromatography?

A solid or liquid phase that stays fixed in place

Which type of chromatography typically uses a thin layer on a plate as its stationary phase and moves the mobile phase by capillary action?

Planar chromatography

What is a chromatogram?

A graphical representation showing the detector's response over time, with each peak corresponding to a different component

Which of the following is TRUE about column chromatography compared to planar chromatography?

It typically uses a packed tube or column and is suitable for high-accuracy and quantitative analysis

What serves as the stationary phase in paper chromatography?

Cellulose in filter paper

Which separation principle is the primary basis for thin layer chromatography (TLC)?

Adsorption chromatography

What is typically used as the detection method for colorless analytes in TLC?

UV light, Iodine chamber, Chemical staining reagents

Which chromatography method has higher resolution and more defined spots?

Thin Layer Chromatography (TLC)

Which feature describes the speed of separation in paper chromatography?

Slower (takes longer to develop)

Which method has a slightly higher cost due to coated plates?

Thin Layer Chromatography (TLC)

What are the three main steps involved in both paper and thin layer chromatography procedures?

Spotting, Development, Detection

For which common use is paper chromatography especially suitable?

Preliminary identification of plant pigments, amino acids, inks

Which chromatography technique is better suited for semi-quantitative analysis?

Thin Layer Chromatography (TLC)

In the development stage of chromatography, how does the solvent move through the stationary phase?

By capillary action

Which detection method for TLC allows you to observe spots directly under a UV lamp, provided the TLC plate has a fluorescent indicator such as F254?

UV light (UV Lamp) detection

In thin-layer chromatography (TLC), what does a higher Rf value indicate about the polarity of the analyte?

The analyte is less polar

After developing a TLC plate, a student stains the plate to visualize amino acids. Which chemical reagent is commonly used for this purpose?

Ninhydrin

Which detection method in TLC is noted as non-destructive and is particularly good for visualizing lipids and hydrocarbons?

Iodine vapor chamber

If a compound traveled 3.0 cm and the solvent front moved 6.0 cm in a chromatography experiment, what is the Rf value of the compound?

0.5

Which type of chromatography uses an inert gas as the mobile phase?

Gas Chromatography

What kinds of compounds are best analyzed using Liquid Chromatography?

Non-volatile, thermally sensitive compounds, Biomolecules, pharmaceuticals, food additives, polymers

Which method generally provides faster analysis for volatile compounds?

Gas Chromatography

What is a primary limitation of Gas Chromatography as compared to Liquid Chromatography?

Not suitable for non-volatile or heat-sensitive compounds

Which type of mass spectrometry interface is commonly used with Liquid Chromatography?

Soft ionization methods (e.g., ESI, APCI)