par Antunes, Marina Venzon;Raymundo, Suziane;de Oliveira, Vanessa;Staudt, Dilana Elisabeth;Gössling, Gustavo;Peteffi, Giovana Piva;Biazús, Jorge Villanova;Cavalheiro, José Antônio;Tré-Hardy, Marie
;Capron, Arnaud;Haufroid, Vincent;Wallemacq, Pierre;Schwartsmann, Gilberto;Linden, Rafael
Référence Talanta, 132, page (775-784)
Publication Publié, 2015-01

Référence Talanta, 132, page (775-784)
Publication Publié, 2015-01
Article révisé par les pairs
Résumé : | A LC-MSMS method for the simultaneous determination of tamoxifen, N-desmethyltamoxifen, 4-hydroxytamoxifen and endoxifen in dried blood spots samples was developed and validated. The method employs an ultrasound-assisted liquid extraction and a reversed phase separation in an Acquity(®) C18 column (150×2.1 mm, 1.7 µm). Mobile phase was a mixture of formic acid 0.1% (v/v) pH 2.7 and acetonitrile (gradient from 60:40 to 50:50, v/v). Total analytical run time was 8 min. Precision assays showed CV % lower than 10.75% and accuracy in the range 94.5 to 110.3%. Mean analytes recoveries from DBS ranged from 40% to 92%. The method was successfully applied to 91 paired clinical DBS and plasma samples. Dried blood spots concentrations were highly correlated to plasma, with rs>0.83 (P<0.01). Median estimated plasma concentrations after hematocrit and partition factor adjustment were: TAM 123.3 ng mL(-1); NDT 267.9 ng mL(-1), EDF 10.0 ng mL(-1) and HTF 1.3 ng mL(-1,) representing in average 98 to 104% of the actually measured concentrations. The DBS method was able to identify 96% of patients with plasma EDF concentrations below the clinical threshold related to better prognosis (5.9 ng mL(-1)). The procedure has adequate analytical performance and can be an efficient tool to optimize adjuvant breast cancer treatment, especially in resource limited settings. |