Supporting Information

Semi-automated set-up for exhaustive micro-electromembrane extractions of basic drugs

from biological fluids

Miloš Dvořáka, Knut Fredrik Seipb,c, Stig Pedersen-Bjergaardb, Pavel Kubáňa*

a Institute of Analytical Chemistry of the Czech Academy of Sciences, v. v. i., Veveří 97, CZ-

60200 Brno, Czech Republic

b School of Pharmacy, University of Oslo, PO Box 1068, Blindern, NO-0316 Oslo, Norway

c Aker Biomarine Antarctic AS, PO Box 496, NO-1327 Lysaker, Norway

Dr. Pavel Kubáň, e-mail: kuban@iach.cz, Tel: +420 532290140, Fax: +420 541212113, Institute

of Analytical Chemistry of the Czech Academy of Sciences, v. v. i., Veveří 97, CZ-60200 Brno,

Czech Republic

Figure S1. Two experimental set-ups used for connecting the microextraction unit with semi-

automated liquid handling system during performance characterization. Set-up I shows detailed

connections of the system without µ-EME electrode and Set-up II with µ-EME electrode.

Set-up I constitutes the simplest possible connection of syringe pump and microextraction unit

whereas set-up II demonstrates connection necessary for semi-automated µ-EMEs, which also

includes the μ-EME electrode. In the Set-up II, two wires (Cu, 150 μm OD and Pt, 250 μm OD)

were examined as the μ-EME electrode, which was stretched through a hole in the silicone

tubing and then threaded between the silicone and the Tygon tubing. Leak-proof connections

between the pump and the extraction units were obtained with the Set-up I and with the Set-up II

using the thinner electrode, whereas leaks were detected for the thicker electrode. This led to

poor precision and accuracy of withdrawn liquid volumes. In addition, no differences in µ-EME

performance were observed for the two electrode materials and for these reasons Cu wire was

used as anode. The Cu wire at the anodic side of the µ-EME system was replaced with new Cu

wire regularly after two weeks of use.

Cu electrode

Silicone tubing

Needle Tygon tubing

Set-up II

PP pipette tip

PP pipette tipTygon tubing

Needle

Set-up I

2

Figure S2. Real-time monitoring of electric currents during µ-EMEs of standard solutions and

biological fluids spiked with different concentrations of nortriptyline, papaverine and

haloperidol. A. Electric currents for 0 – 20 mg/L of the drugs in standard solution. B. Electric

currents for non-spiked urine/plasma and urine/plasma spiked with 10 mg/L of the drugs. µ-EME

conditions: acceptor, 25 mM HCl (1.3 µL); FLM, ENB (2.5 µL); donor, standard solution, urine

and plasma non-spiked/spiked with the three drugs in 10 mM HCl (1.3 µL); extraction voltage,

150 V; extraction time 10 min.

3.53.02.52.01.51.00.50.0

electr

ic cu

rrent

(A)

1086420extraction time (min)

spiked plasma 10 mg/L blank plasma spiked urine 10 mg/L blank urine

3.53.02.52.01.51.00.50.0

electr

ic cu

rrent

(A)

1086420extraction time (min)

20 mg/L 10 mg/L 5 mg/L 1 mg/L 0 mg/L

B

A

3