Instrumental Methods Of Analysis Flashcards
What are some advantages of instrumental methods kf analysis
-> Sensitivity
-> Accuracy
-> Speed
What does sensitivity mean in instrumental methods kf analysis
Being able to tell if a substance is present even if there are very low amounts of it
What does accuracy mean in instrumental methods kf analysis
How close your measured values of a substance is to its true value
What is Speed in instrumental methods of analysis k
How quickly or slowly it takes for the sample to be tested
In gas chromatography what does it Kane if it takes longer for a sample to travel through the column
It has a higher affinity to the stationary phase
What are the stationary phases generally in gas chrmatogrpahy
Silica
Alumina
What does it mean if the gas passes through the column quickly in gas chrmatogrpahy
It has a higher affinity to the mobile phase (carrier gas)
How to tell the amounts of the substance present using a chromatogram
The area under the peaks of the chromatogram
What is the advantage of using gas chrmatogrpahy hover thin layer chrmatogrpahy
-> better resolution
-> autonable
-> more sensitive
-> tells you specific amounts
Why does resolution mean in gas chrmatogrpahy
How separated the components are from eachother
What is a mass spectrometer
A mass spectrometer is used to measure the mass of atoms and molecules
How does a mass spectrometer work
-> ionisation
-> acceleration
-> deflection
-> detection
What is ionisation in mass spectrometry
-> Electrons are fired at the molecules once they are vaporised
-> when the electrons collide, one electron is generally knocked out of its shell
-> the atoms then generally become 1+ ions
What is acceleration in mass specotmrty
-> Ions are accelerated by an electric field
-> this makes sure that all of the ions have the same KE
Deflection
-> the ions then pass through a magnet which is in a band in the tube
-> heavier ions require more magnetism to be bent to follow shape kf tube
-> lighter ions require less magnetism to be bend to follow shape of tube
What happens when magnetic fields is too high in mass spectrometry
if the magnetic field strength is too high, lighter ions will crash into sides of tube
What happens when magnetic fields to low in mass spectrometry
if the magnetic field strength is too low, heavier ions will crash into sides of tube
What is detection in mass spectrometry
When the abundance of each certain ion is detected by a detector
