In-line coupled single drop liquid-liquid-liquid microextraction with capillary electrophoresis for determining fluoroquinolones in water samples

VALERIA H. SPRINGER; ADRIANA G. LISTA

JOURNAL OF CAPILLARY ELECTROPHORESIS

Springer

Año: 2015 vol. 36 p. 1572 - 1579

1079-5383

A simple in-line single drop liquid-liquid-liquid microextraction (SD-LLLME)coupled with capillary electrophoresis (CE) for the determination of two fluoroquinolones was developed. The method is capable to quantify trace amount of analytes in water samples and to improve the sensitivity of CE detection. For the SDLLLME, a thin layer of organic phase was used to separate a drop of 0.1 M NaOH hanging at the inlet of the capillary from the aqueous donor phase. By this way, the analytes were extracted to the acceptor phase through the organic layer based on their acidic/basic dissociation equilibrium. The drop was immersed into the organic phase during 10 min for extraction and then it is directly injected into the capillary for the analysis. Parameters such as type and volume of organic solvent phase, aqueous donor and acceptor phases and extraction time a nd temperature were optimized. The enrichment factor was calculated, resulting 40-fold for enrofloxacin (ENR) and 6-fold for ciprofloxacin (CIP). The linear range were 20 -400 µg·L-1 for ENR and 60-400 µg·L-1 for CIP. The detection limits were 10.1 µg·L-1 and 55.3 µg·L-1 for ENR and CIP respectively and a good reproducibility was obtained (4.4% for ENR and 5.6% for CIP). Two real water samples were analysed applying the new method and the obtained results presented satisfactory recovery percentages (90?100.3%).