Analysis of Energy Drinks for VOC's with the OI Analytical 4760 Eclipse

The regulation of prepared beverages has become a somewhat contentious issue following the discovery of benzene in soft drinks in the 1990s. Though the benzene content is now regulated to 5 ppb, soft drinks are still not broadly held to National Primary Drinking Water Regulations in the USA. As energy drinks are now also a multi-billion dollar growth market in the beverage industry, involving major global companies and specialised manufacturers, the concentrations of volatile organic compounds in such drinks are important to assess.

OI Analytical, a xylem company, has analysed 20 different energy drinks for 85 different volatile organic compounds (VOCs) including benzene. Sample concentration and introduction was carried out using a new OI Analytical 4760 Eclipse Purge and Trap and a 4100 Sample Processor, with an Agilent 5975C Mass Spectrometer and a 7890A Gas Chromatograph subsequently used for separation and detection. The Eclipse successfully circumvents the beverage foaming problem that can occur when analysing by purge and trap methodology.

The Eclipse purges VOCs from liquids (and solid and gas matrices as well) using a regulated flow of an inert gas, helium in this case, for a fixed time period (11 min). Analytes are stripped from the sample concentrate onto a sorbent trap specific for the application. The trap heats rapidly, desorbing the analytes as a “plug” onto the GC column using a reversed carrier gas flow.

The Eclipse is particularly effective for this procedure as its patented Cyclone Water Management™ system removes >96% of water during the thermal desorb step, allowing improved analysis of polar compounds and minimising water transfer to the GC column. Other patented technologies for foam sensing and purge abort help prevent system contamination and the Sparge Overfill Sensor (SOS™) stops overfilling of the sparge vessel and system flooding.

OI Analytical did detect Benzene in two sample drinks. These were at trace levels (2.17 and 1.85 ppb) below the limit of 5 ppb that has been adopted as a standard. Chloroform was also found in several of the energy drink samples at reportable levels (>2 ppb), although this was still well below the United States Environmental Protection Agency maximum contaminant level. The flavouring agent p-cymene was also detected above the reporting limit and most drinks also contained ethanol at appreciable levels (>200 ppb).

Date added: 2017-01-30 12:31:51