Instrumental Analysis Quiz

Can the elution time be shortened and how?

• By increasing the column length

• By using a lower boiling point mobile phase

• By decreasing the temperature of the column

• By using a higher flow rate of carrier gas

Which detector is suitable for the analysis of hydrocarbons?

• Flame ionization detector (FID)

• Thermal conductivity detector (TCD)

• UV/Visible detector

• Electron capture detector (ECD)

What is the main principle of Gas Chromatography?

• Separation based on polarity

• Separation based on volatility

• Separation based on molecular weight

• Separation based on size exclusion

What is the requirement for samples in GC analysis?

• Must be non-volatile

• Must be volatile

• Must be thermally unstable

• Must be ionic

What is the function of the Flame Ionization Detector (FID) in GC?

• Breaks down organic molecules

• Collects ions and produces an electrical signal

• Detects changes in thermal conductivity

• Produces ions in the carrier gas

Why are GC columns longer than HPLC columns?

• To decrease the resolution

• To lower the working temperature

• To reduce the retention time

• To achieve higher separation efficiency

How can the resolution of a Gas Chromatography analysis be improved?

• By using a higher flow rate of carrier gas

• By decreasing the column length

• By increasing the column temperature

• By using a narrower diameter column

What is the purpose of the carrier gas in Gas Chromatography?

• To dissolve the sample

• To provide a medium for sample separation

• To react with the analytes

• To increase the column temperature

How does the Electron Capture Detector (ECD) function in Gas Chromatography?

• By collecting ions and producing an electrical signal

• By dissolving the sample

• By reacting with the analytes

• By detecting changes in thermal conductivity

What effect does increasing the column temperature have on Gas Chromatography analysis?

• Decreases the resolution

• Increases the retention time

• Improves separation efficiency

• Reduces the flow rate of carrier gas