6.3 Analysis

Rf value=distance travelled by spot/distance travelled by solvent

Measured from zero to centre of peak, look up in reference table to identify substance present

Area under peak is proportional to relative amount of each substance

• Create a series of standard solution of different concentration of analyte • One by one inject your standard solution into a gas chromatography instrument and record the result • Calculate the area under the peak of each response for each standard solution • Plus these values on a graph of area vs concentration • Join your plot up to create an external calibration curve

Run a blank. (A solution containing all solvents and reagents used to make standard solution) subtract the response from each response from standard solution to find a correct peak.

Reaction with bromine water Shake test tube Orange to colourless

React with aqueous silver nitrate in ethanol Place in water bath Observe colour precipitate

Weak acidity (dissolve in NaOH) but no reaction with (sodium) carbonates.

Dissolve 0.2g 2,4-DNP, in 1 cm³ of sulphuric acid, 2 cm³ of water and 5 cm³ of methanol In a different test tube add five drops of the unknown substance to 2 cm³ of your solution shake the test tube and watch for a precipitate Orange Check crystalline derivative mp and compare to known value

2 cm³ of 0.1 silver nitrate solution in a test tube add five drops of 0.8 sodium hydroxide solution A light brown precipitative should form Add drops of dilute ammonia solution until the brown precipitate dissolves completely place the tube in the hot water bath and a 10 drops aldehyde wait for a few minutes Silver mirror form

TMZ, tetramethylesaline, Si(CH3)4, As low frequency absorption peak

Run 2 spectre of the molecule one with a little D2O added Peak will disappear due to proton exchange