A one-step protocol for vortex-assisted liquid-liquid microextraction and in-syringe detection. A green determination...

Liquid-liquid microextraction procedures performed in-syringe offer new possibilities for handling samples. They enable different variations of microextraction techniques to be performed based on the requirements of the analysis or the nature of the analyte or sample. However, for detection, the sample has to be removed from the syringe, which complicates the entire process. Additionally, detection frequently requires the use of expensive devices. Therefore, there is a need for further development of inexpensive procedures for trace analysis with simple instrumentation.

A one-step protocol for liquid-liquid microextraction and in-syringe detection using a direct immersion optical probe in the tip is herein presented for the first time. This approach was introduced for vortex-assisted liquid-liquid microextraction of cadmium into the 100 μL of 1-octanol. The calibration curve was linear in the concentration range of 5.0-90 μg L^-1. The limit of detection and limit of quantification were calculated as 0.9 μg L^-1 and 3.0 μg L^-1, respectively. The accuracy (as recovery, %) was between 98.2 and 103.0%, and the precision (as the RSD, %) was less than 5.4% in all cases. The applicability of the method was demonstrated by analyzing tap water, two kinds of mineral water and river water. Finally, the method was evaluated using available tools based on the principles of green and white analytical chemistry and received high overall scores in both cases.

This work presents for the first time a novel strategy for integrating an optical probe for direct detection in a syringe tip. It introduces a one-step protocol for liquid-liquid microextraction and detection, thus minimizing sample handling and the potential for errors. The main advantages of this protocol are its operational simplicity and requirements for inexpensive laboratory equipment. The use of a green solvent and the achievement of a high enrichment factor also highlight the green aspects of the protocol and potential use for routine environmental analyses.