C4.2.4 - Instrumental Method of Analysis Flashcards
What does an instrumental method of analysis rely on?
A machine to carry out the analysis of a substance
What are the advantages of using instrument methods?
Quicker, More sensitive, More accurate
What does the sensitivity of an instrument mean?
How easily it can analyse smaller substances
What are the advantages of a sensitive instrument?
It can analyse small amounts of substances which are expensive or difficult to obtain
What is a gas chromatogram?
A chart which shows the different substances within a mixture
What does each peak represent on a gas chromatograph?
Each system
What does the area under each peak represent on a gas chromatogram?
The amount of the substance within the mixture
What is the retention time on a gas chromatograph?
How long it takes for the substance to travel through the chromatography column
How can you identify a substance by its retention time?
Each substance has its own unique retention time
What does a mass spectrometer do?
Measure the mass of atoms and molecules
What are mass spectrometers used for?
Analysing the relative amounts of different isotopes of an element, and the structure of different molecules
Why is mass spectrometry used in environmental science?
It can be used to detect toxic substances
How do sample molecules turn into molecular ions?
They are ionised by the machine. and broken up into fragments which are separated and detected
What does each peak represent on the mass spectrum?
A fragment of the molecule
What does the peak on the far right of the mass spectrum represent?
The molecular ion
