if a sample has to be dissolved, then the solvent shouldn't contain any 1-H atoms as it will show up on the spectrum
deuterated solvents are often used (the 1-H atom is replaced by D / 2-H) as it doesn't interact with the external magnetic field and make peaks on the NMR spectra
CCl4 can also be used
what is chemical shift
NMR spectroscopy measures differences in the energy absorbed by nuclei in the different environments relative to a standard substance
the difference is called the chemical shift, measured in ppm
the standard substance is tetramethylsilane (TMS)
how to identify the colourless chemicals that can be used in TLC
fluorescentdyes: are visible when UV light is shone
iodine: turns colourless spots purple
what does it mean to elute and elution time?
when a substance in column chromatography leaves the column the liquid is known as the eluent (when they leave they are eluted)
what is TLC
mobile phase: liquid solvent (water or organic)
stationary phase: solid silica (or alumina) gel on glass (or metal) plate
