GC MS

In Gas chromatography the mobile phase is

• Water

• Acetone

• Helium

• Acetylene

In a GC spectrometer during sample injection when some of the sample injected into the injector by the sample syringe gets vaporized and escapes through the split vent it is called .....of injection

The substance in the mixture that has the greatest affinity for the stationary phase will travel

• fastest
• slowest

The retention factor is used

• to zero the chromatography scale
• to identify unknown compounds in a sample
• to retain solvent
• as a starting tool for chromatography

What is chromatography?

• A way to see pretty colors

• A laboratory technique used to separate a mixture.

• A form of distillation

In GC, retention depends upon the

• Vapor pressure and polarity of the solute

• Size and charge of the solute

• The method of sample introduction

• The type of detector used

• Type of column used

In gas chromatography, the basis for separation of the components of the volatile material is the difference in

• partition coefficients

• conductivity

• molecular weight

• molarity

In gas chromatography, the concentration of a substance can be determined by ...

• comparison of the Rt of the substance with that of a standard.

• measurement of the height of the peak produced by the substance.

• comparison of the area under the peak produced by the substance with the areas under the peaks produced by standard solutions.

• calculation of the Rt value of the substance.

The type of chromatography used today in forensics lab is _________________.

• column chromatography

• thin layer chromatography

• paper chromatography

• gas chromatography

If a sample is less polar the choice of the separation column in Gas chromatography should be

• polar column

• non polar column