title: Two different clean-up procedures for liquid chromatographic determination of ochratoxin A in urine.
abstract: This paper describes two different procedures for extraction of ochratoxin A (OTA) from urine samples: one using acidic chloroform-methanol mixture, followed by solid-phase extraction (SPE) clean-up and the other using commercial Chem Elut columns and a chloroform-formic acid mixture. The recovery of OTA using the procedure with silica gel columns was 82% with a R.S.D. < 8.4% and the detection and quantitation limits were 0.5 and 1.5 ng OTA/ml, respectively. The recovery of OTA in the second procedure with urine samples purified only on commercial Chem Elut columns was 95% with R.S.D. < 4.0%, and detection and quantitation limits 0.3 and 0.9 ng/ml, respectively. Both procedures of OTA extraction effectively eliminate interfering substances and give reliable and repeatable results. However, the procedure with Chem Elut columns gave higher recovery and lower detection and quantitation limits. It was successfully applied in determining OTA in human urine samples.
authors.affiliation: Unit of Toxicology, Institute for Medical Research and Occupational Health, Ksaverska c. 2, 10000, Zagreb, Croatia. adomijan@imi.hr
authors.forename: Ana-Marija
authors.initials: AM
authors.lastname: Domijan
authors.forename: Maja
authors.initials: M
authors.lastname: Peraica
authors.forename: Marica
authors.initials: M
authors.lastname: Miletić-Medved
authors.forename: Ana
authors.initials: A
authors.lastname: Lucić
authors.forename: Radovan
authors.initials: R
authors.lastname: Fuchs
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D009793:Ochratoxins / Q000652:urine*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D009793:Ochratoxins; C025589:ochratoxin A