Determination of volatile compounds in rose-water and fruit juices using indirectly suspended droplet microextraction of water-miscible organic solvents by the salting-out effect

In this work, extraction of volatile compounds (alpha-pinene, limonene, linalool, borneol, 2-phenylethanol, thymol and decanoic acid) in rose-water and fruit juices was followed using indirectly suspended droplet microextraction (ISDME). The ISDME is a combination of salting-out extraction of water-miscible organic solvents and directly suspended droplet microextraction (DSDME). A water-miscible organic solvent (2-propanol) was added to the sample solution. A homogeneous solution was formed immediately. A steady vortex was formed by agitation of the solution using a magnetic stirrer. By the addition of ammonium sulfate (saturated solution) to the homogeneous solution, 2-propanol was separated and collected at the bottom of the steady vortex. The effects of important parameters such as water-miscible organic solvents (type and volume), type of salt and extraction time were evaluated. Under optimized experimental conditions, the calibration graphs were linear in the range of 0.05-50.0 mg L-1 with a coefficient of determination of more than 0.9992. Limits of detection and quantification values were in the range of 19-23 mu g L-1 and 63-77 mu g L-1, respectively.