Optimization of solid-phase microextraction procedures for the determination of tricyclic antidepressants and anticonvulsants in plasma samples by liquid chromatography

Abstract

Simple, sensitive, and reproducible off-line solid-phase microextraction and liquid chromatography (SPME/LC) methods are described for the determination of seven anticonvulsants and tricyclic antidepressants in human plasma. Factorial design and simplex methodology were applied in the optimization of the SPME procedure for tricyclic antidepressants analyses. Important factors in the SPME efficiency are discussed, such as the fiber coatings (both lab-made and commercial), extraction time, pH, ionic strength, influence of plasma proteins, and desorption conditions. The development of the lab-made fiber coatings, namely, octadecylsilane, aminosilane, and polyurethane, are further described and applied to anticonvulsants analyses. The investigated plasmatic range for the evaluated anticonvulsants, using CW-TPR fiber, were the following: phenylethylmalonamide (3.00-40.0 microg mL(-1)), phenobarbital (5.00-40.0 microg mL(-1)), primidone (3.00-40.0 microg mL(-1)), carbamazepine and carbamazepine-epoxide (2.00-24.0 microg mL(-1)), phenytoin (2.00-40.0 microg mL(-1)), and lamotrigine (0.50-12.0 microg mL(-1)). The antidepressants' linear plasmatic concentration ranged from 75.0 to 500 ng mL(-1) for imipramine, amitriptyline, and desipramine, and from 50.0 to 500 ng mL(-1) for nortriptyline, being in all cases, the limit of quantification represented by the lowest value. The precision (interassays) for all investigated drugs in plasma sample spiked with different concentrations of each analyte and submitted to the described procedures were lower than 15%. The off-line SPME/LC methodologies developed allow anticonvulsants and antidepressants analyses from therapeutic to toxic levels for therapeutic drug monitoring.

Coupling of solid‐phase microextraction with micellar desorption and high performance liquid chromatography for the determination of pharmaceutical residues in environmental liquid samples

“…LODs obtained for this type of compounds with micellar desorption were in the range 0.05-12 ng mL −1 using POLE and 0.1-5 ng mL −1 using C 12 E 6 . These values were enhanced by a factor ranging between 4 and 10 with respect to those obtained in other works (Queiroz et al, 2002;González-Barreiro et al, 2003;De Oliveira et al, 2005;Delmar Cantú, 2006). LOQs were in the ranges 0.14-36 and 0.4-15 ng mL −1 using POLE and C 12 E 6 , respectively.…”

Construction of different types of ion-selective electrodes and validation of direct potentiometric determination of phenytoin sodium

“…There are some indications that phenytoin has other effects, including anxiety control and mood stabilization, although it has never been approved for those purposes by the FDA [1]. sodium Several methods have been reported for the determination of phenytoin sodium using HPLC [2][3][4][5][6][7], LC-MS [8,9], GC [10][11][12], spectrophotometry [13,14], capillary zone electrophoresis [15], polarography [16], potentiometry [17]. This work describes two different implementation of a new and selective type of membrane sensors: plastic membrane and coated wire electrodes for the determination of phenytoin sodium in pure solutions, pharmaceutical preparations and biological fluids.…”

Determination of anticonvulsants in human plasma using SPME in a heated interface coupled online to liquid chromatography (SPME-LC)

“…In spite of the SBSE bar being coated with a thicker film than that used in this study, their method presented a lower LOD due to the off-line desorption and showed lower performance. Due to the off-line desorption, the same issue was observed in the method reported by Cant u et al 26 using SPME with off-line desorption to determine anticonvulsants and antidepressants in plasma. Our study showed that controlled temperature in the desorption procedure is View Article Online fundamental to completely desorb the compounds, and essential to improve the response at low concentrations.…”

“…SPME has been utilized in the determination of anticonvulsants using either an off-line desorption step followed by LC analysis or directly into a GC injector. Cant u et al 26 used lab-made and commercial SPME fibers for the determination of antidepressants and anticonvulsants in plasma by LC after off-line liquid desorption. The off-line desorption step could introduce errors and present low desorption capacity.…”