MOOC: Instrumental analysis of cultural heritage objects

SELF TEST 5.1

Questions about general theoretical aspects of chromatography.

What type of information from a chromatogram is used for qualitative analysis? (There can be one or more correct answers)

Based on retention time - retention time of a compound is constant under the same conditions, irrespective of the material type

The area of the peak is used for identification

The height of the peak is used for identification

Based on retention time - retention time of the same compound is different in different materials and mixtures, but is always the same in one type of material or mixture

Which types of compounds exit the column first in reversed-phase liquid chromatography (i.e. the mobile phase is more polar than the stationary phase)? (There can be one or more correct answers)

Polar

Non-polar

This cannot be decided based on the polarity

Separation in the GC system is mostly based on… (End the following sentence with the correct option)

... differences in boiling points of the compounds

… differences in polarity

… differences in ionic charge

Which of the following are detectors used for LC systems? (There can be one or more correct answers)

Mass spectrometer (MS) detector

UV-Vis/ photodiode array (PDA) detector

Flame ionisation detector (FID)

Fluorescence detector (FLD)

Energy-dispersive X-ray detector (EDS)

Which of the following are key aspects for achieving separation in LC? (There can be one or more correct answers)

The composition of the mobile phase

Composition of stationary phase

Stationary phase temperature above 300 °C

Only derivatised compounds can be separated

Good separation is achieved with mobile phase with pH 7

Why are buffer solutions used in LC? (There can be one or more correct answers)

So the analysed components would not change the conditions (pH) of the mobile phase

So the sample (solution) would not get contaminated

The instrument would get contaminated without buffer

So the analysed compounds would be in suitable charge state

So that the analysed compounds will be volatile

Which statements are true about a compound that can be analysed with GC (without sample pre-treatment)? (There can be one or more correct answers)

It must be thermally stable

It must be volatile

It must be an organic compound

The boiling point of the compound cannot be below 500°C

It can be analysed by dissolving it in water

Chromatography is a … (There can be one or more correct answers)

… technique for separating compounds from a mixture

… technique that uses mobile and stationary phase for separating compounds

… technique for comparing materials with each-other

… technique for separating compound according to mass-to-charge ratio

Retention time is... (There can be one or more correct answers)

...the time it takes for a compound to pass through the chromatographic column under the set conditions

...the time it takes to dissolve a compound in the chromatographic column

...the time of sample preparation

...the time to generate ions in the chromatographic column

What type of information from a chromatogram is used for quantitative analysis? (There can be one or more correct answers)

Peak area

Peak height

Retention time of the peak

Boiling point of the compound

Peak area – the highest peak in the chromatogram must be used for quantification

Which of the following are detectors used for GC systems? (There can be one or more correct answers)

Mass spectrometer (MS) detector

UV-Vis/ photodiode array (PDA) detector

Flame ionisation detector (FID)

Fluorescence detector (FLD)

Energy-dispersive X-ray detector (EDS)

Which GC or LC detector is described?

This detector can be used for the analysis of compounds that contain at least one C-H or C-C bond. In the detector, the compounds are burned and ionised in a hydrogen flame.	FID Unselect MS Unselect FLD Unselect UV-Vis/PDA Unselect
In this detector, the separated compounds are ionised and the formed ions are sorted by their mass-to-charge (m/z) ratio.	FID Unselect MS Unselect FLD Unselect UV-Vis/PDA Unselect
This detector enables the qualitative and quantitative analysis of different compounds by recording the UV-Vis absorption spectrum (in the range of 190-780 nm) for each chromatographic peak.	FID Unselect MS Unselect FLD Unselect UV-Vis/PDA Unselect
This detector is suitable for the analysis of compounds with fluorescent properties.	FID Unselect MS Unselect FLD Unselect UV-Vis/PDA Unselect

Are the following statement true or false?

In LC|the mobile phase is liquid and the stationary phase is solid.

In LC|the mobile phase is liquid and the stationary phase is liquid.

In GC|the mobile phase is gaseous and the stationary phase is liquid.

In GC|the mobile phase is liquid and the stationary phase is liquid.

In LC|the mobile phase is gaseous and the stationary phase is solid.

Match the following material to the corresponding technique:

Analysis of polymers by decomposing them into smaller fragments.	Py-GC-MS Unselect GC-MS Unselect SPME GC-MS Unselect
Analysis of volatile and semi-volatile compounds thanks to a special fibre that adsorbs them.	Py-GC-MS Unselect GC-MS Unselect SPME GC-MS Unselect
Analysis of volatile, thermally stable compounds with boiling points below 500°C.	Py-GC-MS Unselect GC-MS Unselect SPME GC-MS Unselect

Match the description with the corresponding type of LC technique:

Compounds are separated according to their polarity in a system where the mobile phase is more polar than the stationary phase.	Normal-phase LC Unselect Reverse-phase LC Unselect Ion chromatography Unselect Size exclusion chromatography Unselect
Compounds are separated according to their polarity in a system where the mobile phase is less polar than the stationary phase.	Normal-phase LC Unselect Reverse-phase LC Unselect Ion chromatography Unselect Size exclusion chromatography Unselect
Compounds are separated according to the size of the molecules.	Normal-phase LC Unselect Reverse-phase LC Unselect Ion chromatography Unselect Size exclusion chromatography Unselect
Compounds are separated during an ion exchange process that happens between the sample and the stationary phase.	Normal-phase LC Unselect Reverse-phase LC Unselect Ion chromatography Unselect Size exclusion chromatography Unselect

Course introduction
1. Overview of materials and techniques
2. Optical microscopy
3. Vibrational spectroscopy
- 3.1. IR Spectroscopy
  - * SELF TEST 3.1
- 3.2. Raman spectroscopy
  - * SELF TEST 3.2
4. Elemental and X-Ray methods
5. General aspects of chromatography and mass spectrometry
- 5.1. Chromatography
  - * SELF TEST 5.1
- 5.2. Mass spectrometry
  - * SELF TEST 5.2
6. Practical aspects of chromatography and mass spectrometry
- 6.1. Chromatography
  - * SELF TEST 6.1
- 6.2. Mass spectrometry
  - * SELF TEST 6.2
7. Multimethod analysis
Glossary
Acknowledgements
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