Research Article

Preconcentration and Determination of Psychotropic Drugs in Urine Samples by Ion Mobility Spectrometry with Electrospray Ionization Coupling On-Line Single-Drop Liquid-Liquid-Liquid Microextraction

Figure 3

Concentration profile for NaOH (a) in the donor phase and Ac (b) in the acceptor phase.
(a)
(b)