OI Analytical analyse energy drinks for VOCs using purge and trap sample concentration and GC-MS
30 Jan 2017
OI Analytical has analysed samples of energy drinks to evaluate the concentrations of volatile organic compounds. As beverage foaming makes concentration of such samples difficult this provides the ideal challenge to show the efficacy of the their Eclipse 4760 Purge and Trap and 4100 Sample Processor.
OI Analytical, a xylem company, has used their Eclipse 4760 Purge and Trap and 4100 Sample Processor, in conjunction with GC-MS, to analyse 20 different energy drinks for the presence of 85 different volatile organic compounds (VOCs). The Eclipse is particularly effective for sample preparation and introduction as its patented Cyclone Water Management™ system removes >96% of water during the thermal desorb step, allowing improved analysis of polar compounds, while minimising water transfer to the GC column.
OI Analytical has also developed other patented technologies for foam sensing and purge abort, to help prevent system contamination. The Sparge Overfill Sensor (SOS™) prevents overfilling of the sparge vessel and system flooding.
Purge-and-trap procedures are useful for concentrating VOCs, especially those that are insoluble/poorly soluble in water and have boiling points less than 200°C. However, soft drinks like energy drinks are prone to foaming which can cause difficulties during analysis. Effective analysis of soft drinks is important though as previous studies in the 1990s indicated that benzene could be present in drinks as a contaminant.
In the current study OI Analytical found Benzene in two energy drinks. The amounts present were below the NPDWR limit of 5 ppb that has been suggested as a standard. In addition chloroform was found at reportable levels (>2 ppb) in several of the energy drink samples.
This is still below the United States Environmental Protection Agency (USEPA) maximum contaminant level. Most drinks contained ethanol at appreciable levels (>200 ppb) and the flavouring agent p-cymene was also detected above the reporting limit.
In addition to providing important information on VCO levels in energy drinks, the study clearly shows the efficacy of OI Analytical’s Eclipse 4760 Purge and Trap and 4100 Sample Processor for studying foaming soft drinks.