Abstract
Single-drop micro extraction (SDME) that can archive extraction by contacting continuously a droplet to a sample solution by rotating a spiral extraction cell, after the sample solution has been filled in the extraction cell vertically placed, and then the extracting droplet is introduced in the cell, was examined. Fluorinated alcohols and Malachite green (MG) were used as the extraction solvent and model sample, respectively. After MG in 20% NaCl aqueous solution (2.5 μM) was filled in a glass extraction cell (2.6 mm i.d. ; 1.8 m long ; 9.3 mL of the net volume ; and 10 cm of the diameter of spiral), 3.0 μL of a droplet of 2,2,3,3,4,4,5,5-octafluoro-1-pentanol (OFP) as the extracting solvent was introduced into the cell. After introduction, extraction was performed for four minutes by moving the droplet at a rate of 1.5 cm/s in one roundtrip by rotating the extraction cell at room temperature. In this case, an enrichment factor (the ratio of the concentrations in the droplet and the sample solution, before and after the extraction, respectively) was obtained to be 0.54 × 103. On the contrary, when a droplet (0.96 μL) of 1H,1H-pentadecafluoro-1-octanol (PDFO) was used as the extracting media, and them similar extraction was performed at 65°C, the enrichment factor was estimated to be 1.6 × 103. A PDFO droplet after the extraction was solidified by cooling to room temperature, therefore, it was possible to separate by filtration as a spherical particle.
