Chemistry (6.3): Analysis

Types of chromatography (2)

Types of chromatography (2)

1. thin layer chromatography

2. gas chromatography

Phases of chromatography (2)

1. stationary

2. mobile

stationary phase

fixed in place

mobile phase

moves in a definite direction

stationary phase of TLC

silica mounted on a glass plate

mobile phase in TLC

suitable organic solvent

R_f =

distance travelled by the component / distance travelled by the solvent

stationary phase of gas chromatography

liquid adsorbed on an inert solid

mobile phase of gas liquid chromatography

gas

retention time

the time taken for a component to travel from the inlet to the detector in a gas chromatograph

TMS

an internal standard for both carbon and proton NMR

deuterium

an isotope of hydrogen and does not produce a signal in the proton NMR

TMS

tetramethylsilane

What is used as a standard in NMR?

TMS

Why is TMS a good internal standard?

1. contains C and H so used for both C and proton NMR

2. produces sharp signal and H in single environment

3. non-toxic

4. low bp, so volatile, so easily removed from sample

5. inert

Types of NMR

carbon and proton

number of peaks in the splitting pattern =

number of protons on adjacent carbon atom + 1

How do you identify between -OH and NH protons?

D₂O