Analysis of organic acids using gas chromatography

Gas chromatography is also suitable (as is HPLC) for separating volatile and non-volatile organic acids. There is no standard method and it should 

In the method described below, samples are first passed through an anion exchanger and then esterified before the GC analysis takes place. 

For the exchange resin put 2 - 3 g XAD-4 into a glass column (12 cm 0.8 cm) and pass 200 ml of the sample (waste water) or 1 - 4 litres (surface water) through the exchanger at a rate of 4 - 3 ml/min. 

Wash through with 25 ml diethyl ether, then with 23 ml methanol and finally again with 23 ml diethyl ether. 

Extract the sorbed anions with 20 ml diethyl ether saturated with HCl. Return this eluate to the column and wash through with ether-HCl. 

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