A well-known colour reaction of aromatic compounds is that with forrnalin solution and concentrated sulphuric acid. T\_EI Cl\itr;rosL quote it for chromatogmphic work anti I~x~xc;r~~ gives an cxtcnsivc list of aromatic compounds showing the test, using the same reagent quantities as LEICOSIS~ and co-workers, naniely, 0.2 ml of 37OA, formalin solution and x0 ml of conccntratcd sulphuric acid.
As a basis for quantitative analysis, the reaction has been httle used. It serves for approximate analysis of bcnzcnc and other lower aromatic hydrocarbon9. MOI<RIS, STILES AND LAXI@ have us~l it to clctcrminc small amounts of these hydrocarbons in water by cstraction with carbon tctrachloridc (25 ml) and dcvcIopmcnt of colour with 5 ml of a mixture prcparccl from f ml of .37');, formalin f-ioo ml concentrated sulphuric acid, It was considered of interest to examine more fully the possibility of using the colour reaction as a basis for the analysis of: (if Aromatic compounds in the prescncc of non-aromatic. (ii) One aromatic compound, reacting mot-c sensitively, in the prcsencc of other, less reactive aromatic compounds.
Anisolc, a compound otflerwisc clifficult to analyst in microquantities, was chosen for the initial work.