Rapid Extraction and Analysis of Volatile Solutes with an Effervescent Tablet

Abstract

Extraction of volatile compounds from complex liquid matrices is a critical step in volatile compound analysis workflows. Recently, green chemistry principles are increasingly implemented in extraction processes. Some of the available approaches are solvent-free but still require concentration or trapping of analytes. Here, we propose effervescent tablet-induced extraction (ETIE) as a method of transferring volatile/semivolatile compounds from liquid matrices to the gas phase for analysis. This technique relies on the release of carbon dioxide produced in situ during a neutralization reaction, which occurs when a tablet is inserted into an aqueous sample matrix. In this process, many bubbles of carbon dioxide are instantly formed in the sample matrix. The bubbles rapidly extract and liberate volatile compounds from the sample. The gaseous effluent is then immediately transferred to a detector (atmospheric pressure chemical ionization mass spectrometry (MS) or gas chromatography (GC) hyphenated with MS). ETIE-GC-MS can be used for analysis of volatile compounds present in real samples. The method was validated for analysis of selected ethyl esters present in a yogurt drink. The calibration data set was linear over a range from 5 x 10(-7) to 1 X 10(-5) M. The limits of detection ranged from 1.51 X 10(-7) to 6.82 X 10(-7) M, while the recoveries ranged from 71 to 118%. Inter- and intraday precision of selected ethyl esters in aqueous solution was satisfactory (relative standard deviation, 3.6-18.3%). Furthermore, it is shown that ETIE improves the performance of headspace solid-phase microextraction while eliminating the need for heating and shaking samples.