17.7 Flashcards
high energy mass spec
gives Mr to a higher level of accuracy
gas chromatography
coiled collum inside an oven
sample inserted by syringe
carried through and out the collum in a stream of inert gas
flame ionisation detecter detects them as they leave
signals are plotted by a recorder
each sample represented by a peak
mobile phase then a stationary phase
different retention times
nmr
atoms with odd number of nucleons(protons and neutrons) have a property called spin
these behave like tiny magnets
dissolved in a deuterium solvent
reference must be unreactive - same peak e.g tms
carbon 13 nmr
number of peaks - number of carbon envirmonets in molecule
size of peaks are number of carbon atoms causing that peak
spin spin splitting - h nmr
high resolution
no of n+1 peaks = the amount of hydrogens on the adjacent carbon atom
number of peaks = number of hydrogen environments
area under = number of hydrogens in that environment
retention time
amount of time in the collum
depends on polarity for the stationary phase
greater attraction for the stationary phase (higher charge) the greater the retention time
high boiling temp means less time in the gas phase/mobile so longer retention time
gas carriers
innert
locating agent
ninhydrin
used to locate amino acid spots
ion peaks
+ charge
isotopes
do punnet square for abundance
peak area
overall number of hydrogens
area 4 = ch4 or 2xch2
compare spectrums
Carbon enviroments
hydrogen enviroments
splitting patterns
peak ratios
chemical shifts
stationary and mobile phases
stationary is solid or liquid coated on inside of tube
mobile phase is inert carrier gas
chemical shift
indicates its behavior in a magnetic field relative to tetramethylsilane (=0)
integration trace
horizontal line that beomes higher as it passes each peak
increase in hight represent the area under the peak
equivalent protons
hydrogens in the same carbon enviroment
