For identification use spectrophotometer, Alcohol have maximum absorbance at 230 nm and ethanol at 240 nm, water is as reference . For quantification take sample add sulfuric acid and potassium dichromate mix solution, close the flask with stopper store the flask overnight and add potassium iodide about 20%, starch solution as an indicator and titrate with 0.1 M sodium thiosulphate solution.

You can check quantity of alcohol by HPLC and its purity by GC method.