Article

Stir bar sorptive extraction and liquid chromatography with UV detection for determination of antidepressants in plasma samples.

Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040-901, Brazil.
Journal of Chromatography B (Impact Factor: 2.49). 06/2007; 850(1-2):295-302. DOI: 10.1016/j.jchromb.2006.11.042
Source: PubMed

ABSTRACT A sensitive and reproducible stir bar sorptive extraction and liquid chromatography (SBSE/LC-UV) method is described for the determination of sertraline, mirtazapine, fluoxetine, citalopram, paroxetine, imipramine, nortriptyline, amitriptyne, and desipramine in plasma samples. Important factors in the optimization of SBSE efficiency are discussed, such as extraction time, pH, ionic strength, influence of plasma proteins, and desorption conditions: solvents, modes (magnetic stir, ultrasonic), time, and number of desorption steps. The SBSE/LC-UV method showed to be linear in a concentration ranging from the limit of quantification (LOQ) to 1000.0 ng mL(-1). The LOQ values ranged from 10.0 ng mL(-1) to 40.0 ng mL(-1). The inter-day precision of the SBSE/LC-UV method presented coefficient of the variation lower than 15%. Based on figures of the merit results, the SBSE/LC-UV methodology showed to be adequate to the antidepressants analyses from therapeutic to toxic therapeutic levels. In order to evaluate the proposed method for clinical use, the SBSE/LC-UV method was applied to the analysis of plasma samples from elderly depressed patients.

0 Bookmarks
 · 
78 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: A new micro-solid phase extraction method was developed by combining solid-phase extraction and stir bar sorptive extraction to benefit from the advantages of both techniques. A polypyrrole coating was electrochemically synthesized on the surface of an already used graphite furnace, employed in electro-thermal atomic absorption spectroscopy. The cylindrical geometry of the graphite tube provided a rather huge surface area, suitable for sorptive extraction. The novel sorbent coating was examined as an extracting medium to isolate malathion. Effects of different parameters such as extraction time, salt concentration, sample volume, desorption solvent and time were investigated and optimized. Under the optimized conditions, the limit of detection and limit of quantification of the developed method were 5 and 20 ng L−1, respectively. The calibration curve showed linearity in the range of 0.1–100 μg L−1 (R 2 = 0.9968). The precision was evaluated at 0.1 and 1 μg L−1 concentration levels and relative standard deviations (n = 3) were found to be 10 and 7%, respectively. The developed method was successfully applied to the extraction of malathion from real river water and tap water samples, and relative recoveries at the spiked level of 0.1 μg L−1 were 94 and 97%, respectively.
    Chromatographia 01/2011; · 1.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sample preparation is an important step of any biomedical analysis. Development and validation of fast, reproducible and reliable sample preparation methods would be very helpful in increasing productivity. Except for a few direct injection methods, almost all biological samples should at least be diluted before any analysis. Sometimes dilution is not possible because of the low concentration of the target analyte in the sample, and alternative pretreatments, such as filtration, precipitation and sample clean up using different extraction methods, are needed. This review focuses on the recent achievements in the pretreatment of biological samples and investigates them in six categories (i.e., dilution, filtration/dialysis, precipitation, extraction [solid-phase extraction, liquid-liquid extraction], novel techniques [turbulent flow chromatography, immunoaffinity method, electromembrane extraction] and combined methods). Each category will be discussed according to its productivity rate and suitability for routine analysis, and the discussed methods will be compared according to the mentioned indices.
    Bioanalysis 01/2014; in press. · 3.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A fast and efficient method for the determination of tricyclic antidepressants using electro-enhanced solid phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) has been developed. One advantage of this approach is that the mass transfer of target analytes from the sample solution to an SPME fiber can be accelerated by the electrical field, improving extraction selectivity and efficiency. In the present work, the target analytes extracted to the SPME fiber were thermally desorbed in the GC injection port after extraction. Under the optimized extraction conditions, the developed method exhibited low limits of detection (between 0.079 and 0.296μg/L) and good linearity over the concentration range of between 1 and 500μg/L with coefficients of determination (r(2)) of between 0.993 and 0.999. The relative standard deviations were lower than 9.2% for all analytes. The proposed method was applied to extract tricyclic antidepressants in environmental water samples.
    Journal of chromatography. A. 05/2014;