A known carcinogen, benzene must be controlled so human exposure is limited. It can be formed from the decarboxylation of sodium or potassium benzoate preservatives in the presence of ascorbic acid when exposed to heat and light. These combinations are possible with some beverage products. Due to the liquid matrix, sample preparation techniques such as SPE and SPME are useful as they can be used to both extract and concentrate analytes. GC analysis is the typical analysis technique.