Do you know GLME?

Sample pretreatment before chromatographic analysis is the most time-consuming and error-prone part of analytical procedures, and then a key factor in the final success of the analysis. The Analytical Chemistry group of Yanbian University has developed in the last decades (and in cooperation with the University of Foggia since 2014) different and innovative microextraction techniques. Pioneering studies in 2009 described a gas flow headspace liquid phase microextraction (GF-HS-LPME) apparatus where the extracting gas phase volume was increased using a gas flow able to extract simultaneously both volatile and semivolatile chemicals from a sample matrix. Then, in 20112, a quantitative and fast liquid phase microextraction technique named gas purge microsyringe extraction (GP-MSE) was developed for simultaneous direct GC-MS analysis of volatile and semivolatile chemicals without the need for any further cleanup process. In GP-MSE, a 100 μL microsyringe is used as a “holder” and “protector” of the organic solvent. Target compounds were brought from the sample, which can be heated to 300 °C, into the microsyringe needle by inert gas flow, and are quantitatively trapped by the extraction solvent. This technique led to quantitative recoveries of both volatile and semivolatile chemicals in an extraction time of only 2 min. In the wake of these innovations, an upgraded version of GP-MSE called gas-liquid microextraction (GLME), has been proposed for the first time in 20203. Compared with GP-MSE, in GLME the microsyringe is replaced with a 150 μL receiving vial, whose temperature is also perfectly controlled by a refrigerating system (to a minimum of -4 °C). Gas extracting flow (usually nitrogen) can be modulated from 0.1 to 5.0 mL min-1. After the extraction process, vials can be directly placed into the GC or HPLC autosampler for analysis. GLME is a patented technique already available in China and different companies in Europe and USA are evaluating the possibility to open the market for this device in new territories.