title: A liquid chromatography method with single quadrupole mass spectrometry for quantitative determination of indomethacin in maternal plasma and urine of pregnant patients.
abstract: A liquid chromatography with single quadrupole mass spectrometry method was developed for the quantitative determination of indomethacin in the maternal plasma and urine of pregnant patients under treatment. A deuterium-labeled isotope of indomethacin (d4-indomethacin) was used as an internal standard. The maternal plasma and urine samples were acidified with 1.0M HCl then extracted with chloroform to achieve the extraction recovery range of 94-104% with variation less than 11%. Chromatographic separation was achieved by a Waters Symmetry C₁₈ column with isocratic elution of 0.05% (v/v) formic acid aqueous solution and acetonitrile (47:53, v/v). An in-source fragmentation was applied on the single quadrupole mass spectrometer equipped with an electrospray ionization source at positive mode. The LC-ESI-MS quantification was performed in the selected ion monitoring mode targeting ions at m/z 139 for indomethacin and m/z 143 for its internal standard. The calibration curves were linear in the concentration ranges between 14.8 and 2.97 × 10(3) ng/mL for plasma samples and between 10.5 and 4.21 × 10(3) ng/mL for urine samples. The relative standard deviation of this method was less than 8% for intra- and inter-day assays, and the accuracy ranged between 90% and 108%.
authors.affiliation: Department of Obstetrics & Gynecology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0587, USA.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Wang
authors.forename: Daria I
authors.initials: DI
authors.lastname: Vernikovskaya
authors.forename: Tatiana N
authors.initials: TN
authors.lastname: Nanovskaya
authors.forename: Erik
authors.initials: E
authors.lastname: Rytting
authors.forename: Gary D V
authors.initials: GD
authors.lastname: Hankins
authors.forename: Mahmoud S
authors.initials: MS
authors.lastname: Ahmed
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D006801:Humans; D007213:Indomethacin / Q000097:blood* / Q000652:urine*; D013058:Mass Spectrometry / Q000379:methods*; D011247:Pregnancy; D012015:Reference Standards
chemical_list: D007213:Indomethacin