A validated LC–MS/MS method for rapid determination of methotrexate in human saliva and its application to an excretion evaluation study

Tenofovir Disoproxil Fumarate Is a New Substrate of ATP-Binding Cassette Subfamily C Member 11

“…Supernatants were collected, and intracellular concentrations of tenofovir and methotrexate were determined by validated liquid chromatography coupled with tandem mass spectrometry as described previously (14)(15)(16)(17)43). The reference method was validated (14,17,43,44), the lower limits of quantification were determined, and the calibration curves demonstrated linearity, with average correlation coefficients greater than 0.99 for both drugs. Chromatographic separation of tenofovir and methotrexate was achieved by using a mobile phase of acetonitrile-1 mM ammonium acetate buffer in water at pH 6.5 Ϯ 0.3 (50:50, vol/vol) and acetonitrile-1 mM ammonium formate containing 0.1% formic acid (18:82, vol/vol), respectively.…”

UPLC-MS/MS Analysis of Methotrexate in Human Plasma and Comparison with the Fluorescence Polarization Immunoassay

“…Moreover, the signal-to-noise ratio of LLOQ samples was high despite dilution during sample processing; therefore, an one-step protein precipitation by methanol could be used, which was more convenient and economical than previous methods. 6,12 Acetonitrile was used for separation in most of the published studies, 4-6,8-11 whereas a more economical solvent methanol was used in the present study. 12 The whole run time of a sample was 3.0 min, which was faster than most of the previous methods.…”

“…Various kinds of methods have been used for plasma MTX determination, including fluorescence polarization immunoassay (FPIA), 2 high-performance liquid chromatography (HPLC), 3 liquid chromatography tandem mass spectrometry (LC-MS/ MS), [4][5][6][7][8][9][10][11][12] capilary electrophoresis with laser-induced fluorescence detection, 13 and chemiluminescent microparticle immunoassay. 14 In clinical practice, FPIA is the most commonly used method in plasma MTX monitoring owing to its simplicity in sample preparation and a relatively short run time.…”

“…4,8,9,19 With powerful selectivity and sensitivity, many LC-MS/MS methods were developed to determine plasma MTX. [4][5][6][7][8][9][10][11][12]19 However, there were many limitations in previous methods, such as the relatively large sample volume requirements, 6,9,12 the time-consuming process in sample preparation, 6,12 and a long turnaround time in analysis. [4][5][6][7][8][10][11][12]19 In the present study, an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the analysis of MTX in human plasma was developed, validated and applied in 172 samples, which were also tested by FPIA.…”

Determination of Methotrexate at a Silver Solid Amalgam Electrode by Differential Pulse Voltammetry

“…The most widely used analytical methods for its determination are liquid chromatography and high- Merás, Mansilla, and Gómez 2005) and mass spectrometry (Turci, Micoli, and Minoia 2000;Koufopantelis et al 2009;Rodin et al 2013). Other techniques such as spectrophotometry (Sastry 60 and Lingeswara Rao 1996), capillary zone electrophoresis (Flores et al 2005), and immunoassays (Bore et al 1984;Eksbors et al 1996) have also been used for methotrexate determination.…”