We developed and validated an UHPLC-MS/MS method for the quantification of phosphatidylethanol (PEth) in dried blood spots (DBS). Sample preparation was a liquid extraction and chromatographic separation was performed in an Acquity C8 column. The mobile phases were 4 mM ammonium acetate in water (A) and acetonitrile (B) at 24:76 (v/v). The total analytical run time was 6 minutes, with retention time of 3.36 min for PEth and 4.13 min for phosphatidylpropanol. The method was linear from 10 to 3000 ng mL-1, specific, with, precise and accurate. The analyte was stable in DBS stored from -20 to 45 °C for 21 days. Matrix effect was compensated with the internal standard (-5.21% to + 6.09%). The method was applied in the evaluation of alcohol consumption in DBS from 25 chemical dependents. The PEth concentrations ranged from 14.5 to 2380.8 ng mL-1, with significant correlation with the self-report alcohol consumption AUDIT scores (r=0.41).

A highly sensitive ultra-performance liquid chromatography tandem mass spectrometry method for the determination of Docetaxel and metabolites (M1+M3) in human plasma samples was developed and validated. The method employs a liquid-liquid extraction and a reversed phase separation Acquity® C18 column BEH C18 (150 x 2.1 mm, 1.7 µm). Mobile phase was a mixture of formic acid 0.1% (eluent A) and acetonitrile plus 0.1% formic acid (eluent B) in isocratic mode. Total analytical run time was 7 min. The interval of method linearity interval was 50 to 3000 ng mL-1 for docetaxel and 5.0 to 300 ng mL-1, for M1+M3 metabolites. Intra-assay and inter-assay precision was coefficient of variation 2.5-15.7% and 5.9-12.6%, respectively and accuracy was 89.0-114.0%. The method was successfully applied in the measurement of docetaxel plasma levels and area under the curve calculation in 31 cancer patients, demonstrating adequate analytical performance for the clinical application in the therapeutic drug monitoring and pharmacokinetics studies.

Um método simples, sensível e seletivo para determinação de voriconazol em plasma e fluido oral empregando cromatografia líquida de ultra-eficiência foi desenvolvido e validado. Após extração líquido-líquido do plasma e fluido oral com metil-tert-butil éter, o analito e o padrão interno foram separados numa coluna Hypersil Gold C18 (2,1 100 mm, d.p. 1,9 µm), eluída isocraticamente com uma mistura de tampão fosfato trietilamônio pH 3,0 e acetonitrila (70:30, v/v). O tempo total da análise foi de 4 min, com consumo total de fase móvel de 2,2 mL. A determinação foi realizada com detector de arranjo de fotodiodos com quantificação em 256 nm. As concentrações de voriconazol no fluido oral foram, em média, 57,5% (± 5,3) daquelas determinadas em amostras pareadas de plasma.

A simple, sensitive and selective ultra-performance liquid chromatography method for the determination of voriconazole in plasma and oral fluid was developed and validated. After a liquid-liquid extraction with methyl-tert-butyl ether, the analyte and internal standard were separated on a Hypersil Gold C18 column (2.1 × 100 mm, p.d. 1.9 µm), eluted with a mobile phase composed of thietylammonium phosphate buffer and acetonitrile (70:30, v/v). Total run time was 4 min, total mobile phase consumption of 2.2 mL. Detection was performed with a photodiode array detector with quantitation at 256 nm. Voriconazole concentrations in oral fluid were on average 57.5% (±5.3) of those measured in paired plasma samples.

Um método rápido para a determinação de seis inibidores de protease (indinavir, amprenavir, saquinavir, atazanavir, lopinavir e ritonavir) e de dois inibidores não-nucleosídicos da transcriptase reversa (efavirenz e nevirapine), empregando cromatografia líquida de ultra-eficiência com detector de arranjo de diodos foi desenvolvido e validado. Após extração liquido-líquido de 0,5 mL de plasma com metil-tert-butil éter, os analitos foram separados em uma coluna ACQUITY UPLC BEH® C18 (2,1 × 150 mm, d.p. 1,7 μm), eluída com um gradiente de tampão fosfato trietilamônio pH 3.0 e acetonitrila. O tempo total de análise cromatográfica foi de 9,5 min. As curvas de calibração foram lineares entre 0,1 a 10,0 μg mL-1. O limite inferior de quantificação foi 0,1 μg mL-1 para todos os fármacos. A exatidão esteve entre 94,9 e 103,5%. Os coeficientes de variação intra e inter-dias foram inferiores a 7,7% para todos os analitos. Os rendimentos de extração foram superiores a 88,2%.

A fast ultra-performance liquid chromatographic with diode-array detection method has been developed and validated for the determination of six protease inhibitors (indinavir, amprenavir, saquinavir, atazanavir, lopinavir, and ritonavir) and two non-nucleoside reverse transcriptase inhibitors (efavirenz and nevirapine). After liquid-liquid extraction of 0.5 mL plasma with methyl-tert-butyl ether, the analytes were separated on a ACQUITY UPLC BEH® C18 column (2.1 × 150 mm, p.d. 1.7 μm) column eluted with a gradient of acetonitrile and triethylammonium phosphate buffer 5 mmol L-1 pH 3.0. The total run time was 9.5 min. Calibration curves were linear in the range 0.1 to to 10.0 μg mL-1. The lower limit of quantitation was 0.1 μg mL-1 for all drugs. Accuracy ranged from 94.9 to 103.5%. Both interday and intraday coefficients of variation were less than 7.7% for all analytes. The extraction yields were greater than 88.2%.