Analytical Techniques Flashcards
what is a presumptive test?
either discovers what the wrong answer is, or discovers a possible solution,
this means this cannot be used in court.
what is the Kastle-Meyer test?
sample is collected using a swab.
a drop of phenolphthalein is added.
after a few seconds a drop of H2O2 is added.
if the sample turns pink rapidly then blood is present.
what is spectroscopy
study of the way in which electromagnetic radiation interacts with matter.
what is IR spectroscopy ?
used to determine function groups in chemistry by measuring the vibrations of atoms.
stronger bonds will vibrate at
vibrations on the IR spectrum must have a change in ____ movement
dipole
what us UV spectroscopy used for ?
measures the chemical properties of a material by measuring how much light it absorbs at different wavelengths. e.g. drug detection
what is the equation for the Beer-Lambert Law ?
T = S/So
where T is transmittance
S is transmitted intensity \
So is incident intensity
what is the absorbance version of the beer-lambert law ?
A = -logT
what is the I in NMR spectroscopy and what much it be to be NMR active ?
the intrinsic angular momentum number, known as spin.
must beg above 0
NMR - what does the number of peaks show?
number of different types of species
NMR - what does the hight of each peak show ?
the relative number of nuclei.
what’s the difference between minor, major and trace
major - techniques provides info on major part of the compound (above 1%)
minor - tech provides info on minor part of the compound (0.1-1%)
trace - tech provides info of trace part of compound (<0.1%, (ppm))
what is the primary selection rule used for IR spectroscopy
vibrations must have a change in dipole movement to be capable of absorbing electromagnetic radiation.
what are the 3 factors to consider for NMR
- chemical shift
- integration
- splitting
