Myung, SW Kim, M Cho, HW Park, J 2024-01-21T19:08:14Z 2024-01-21T19:08:14Z 2022-01-11 1996-12 0253-6269 https://pubs.kist.re.kr/handle/201004/144211 A sensitive method has been developed for the detection and determination of niflumic acid (NA) in human urine. Samples were extracted with diethylether. Flunixin (FN) was added to the sample prior to extraction as an internal standard. Niflumic acid was converted to its methyl derivative and analyzed by capillary gas chromatography/negative chemical ionization mass spectrometry. Using selected ion monitoring (SIM), the levels of NA down to 5 pg/ml could be detected in 5 mi spiked urine sample. Calibration curve was linear over the range of 0.5 ppm-50 ppm. The recovery of niflumic acid from urine at 40 pg/ml was to be 91.7+/-3.8(n=3) and the coefficient of variation was 4.1%. English PHARMACEUTICAL SOCIETY KOREA Determination of niflumic acid in human urine by gas chromatography negative chemical ionization mass spectrometry Article 10.1007/BF02986030 1 ARCHIVES OF PHARMACAL RESEARCH, v.19, no.6, pp.566 - 569 ARCHIVES OF PHARMACAL RESEARCH 19 6 566 569 scie scopus A1996WA52700024 2-s2.0-20544457581 Chemistry, Medicinal Pharmacology & Pharmacy Pharmacology & Pharmacy Article niflumic acid metabolite GC/MS negative chemical ionization