Application of carbon nanotubes-ionic liquid hybrid in a sensitive atorvastatin ion-selective electrode.
Atorvastatin (ATR) was determined by a potentiometric method. The ion-pair of ATR and cetyltrimethylammonium bromide (CTAB) was used as a suitable ionophore. A graphite paste electrode was modified with ATR-CTAB ion-pair, multiwalled carbon nanotubes (MWCNTs), and an ionic liquid, 1-butyl-3-mtehyl-imidazolium hexafluorophosphate (BMIMPF6). The amounts of electrode ingredients were optimized (graphite powder: paraffin oil: ATR-CTAB: MWCNTs: BMIMPF6 (58:26:5:8:3 w/w%). Surface characterization was done by using scanning electron microscopy. The potential measurements were recorded at optimized pH by using acetate buffer solution (0.1molL(-1), pH5.5). At the above experimental conditions, calibration curve (E vs. log [ATR]) was linear (R(2)=0.9977) in the concentration range of 1.0×10(-9)-1.0×10(-3)molL(-1) (0.0012-1209mgL(-1)) of ATR with a Nernstian slope of 58.14±0.2mV decade(-1), and detection limit of 1.0×10(-9)molL(-1) (0.0013mgL(-1)). After each injection of ATR to the buffer solution, the potential was stabilized in a very short time (average response time~6s) at 25°C. The modified graphite paste electrode had a long lifetime (>4months). Recovery of the spiked drug to blood serum samples (95.3-98.2%) revealed the reliability of electrode response to ATR. Blood serum samples from consumers were analyzed by the proposed method; the results were comparable with those from HPLC standard method. The potentiometric analysis of ATR tablets by the proposed electrode resulted in a relative error of 0.8% and 1.5% for 20 and 40mg per tablets, respectively. Finally, the electrode was used in potentiometric titration of ATR (1.0×10(-3)molL(-1)) by CTAB (1.0×10(-3)molL(-1)). Excellent accuracy (≈100%) was obtained from the volume of the titrant at the endpoint.
Department of Chemistry, Razi University, Kermanshah 671496734, Iran. Electronic address: fjalali@razi.ac.ir.
Fahimeh
F
Jalali
Department of Chemistry, Razi University, Kermanshah 671496734, Iran.
Moslem
M
Ardeshiri
D000069059:Atorvastatin / Q000032:analysis* / Q000097:blood / Q000652:urine; D006108:Graphite / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017736:Ion-Selective Electrodes; D052578:Ionic Liquids / Q000737:chemistry*; D057230:Limit of Detection; D008855:Microscopy, Electron, Scanning; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011199:Potentiometry / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D013499:Surface Properties; D013607:Tablets / Q000737:chemistry
D052578:Ionic Liquids; D037742:Nanotubes, Carbon; D013607:Tablets; D006108:Graphite; D000069059:Atorvastatin
Atorvastatin; Graphite paste electrode; Ionic liquid, blood serum; Multi-walled carbon nanotubes; Potentiometry; Urine