Development of aLiquid-Liquid Microextraction Method Based on aSwitchable Hydrophilicity Solvent for the Simultaneous Determination of 11 Drugs in Urine by GC-MS

A new and green liquid-liquid microextraction method based on aswitchable hydrophilicity solvent for thedetermination of 11 drugs in urine is presented for the first time. The protonated N,N-dimethylcyclohexylamine was used as an extraction solvent and sodium hydroxide was injected as a trigger for organic-phase separation. The extraction procedure has been optimized and investigated in this study. The intraday and interday recovery ranged from 73.8 to 103.0% and the relative standard deviations were in the range from 2.2 to 13.5% (n=5). The linear range was from 5.0 to 2000.0 mu g L-1, and R-2 wasgreater than 0.99, and the limit of detection was in the range from 0.36 to 12.50 mu g L-1. The proposed method may be a useful procedure for the determination of 11 drugs in urine, and easily incorporated into routine testing for a laboratory. [GRAPHICS] .