Capillary electrophoresis connected with tandem mass spectrometry was employed for the development of a method for determination of various tyrosine kinase inhibitors in plasma samples. A stacking online preconcentration with a 120 cm-long capillary was used for the determination of bosutinib, dasatinib, canertinib, and erlotinib at physiologically relevant concentrations. The optimization included both capillary electrophoresis and mass spectrometry steps. Under optimal conditions, 50 mM formic acid pH 2.5, an injection time of 120 s, and an optimized mass spectrometry set-up (as sheath liquid composition 75:24.9:0.1 (v/v) methanol, water, formic acid, and appropriate conditions for ion transitions), LODs in a range of 3.9-23.0 nmol·L-1 were observed. The method was validated in terms of linearity, limit of detection, limit of quantification, repeatability of migration times and peak area, and recovery using plasma as a matrix for analytes. The results showed that this method has great promise for use in many analytical tasks, e.g., therapeutic drug monitoring.

• Klíčová slova
• capillary electrophoresis, mass spectrometry, online preconcentration, stacking, tyrosine kinase inhibitors,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Prediagnostic steps in suspected metachromatic leukodystrophy (MLD) rely on clinical chemical methods other than enzyme assays. We report a new diagnostic method which evaluates changes in the spectrum of molecular types of sulfatides (3-O-sulfogalactosyl ceramides) in MLD urine. METHODS: The procedure allows isolation of urinary sulfatides by solid-phase extraction on DEAE-cellulose membranes, transportation of a dry membrane followed by elution and tandem mass spectrometry (MS/MS) analysis in the clinical laboratory. Major sulfatide isoforms are normalized to the least variable component of the spectrum, which is the indigenous C18:0 isoform. This procedure does not require the use of specific internal standards and minimizes errors caused by sample preparation and measurement. RESULTS: Urinary sulfatides were analyzed in a set of 21 samples from patients affected by sulfatidosis. The combined abundance of the five most elevated isoforms, C22:0, C22:0-OH, C24:0, C24:1-OH, and C24:0-OH sulfatides, was found to give the greatest distinction between MLD-affected patients and a control group. CONCLUSIONS: The method avoids transportation of liquid urine samples and generates stable membrane-bound sulfatide samples that can be stored at ambient temperature. MS/MS sulfatide profiling targeted on the most MLD-representative isoforms is simple with robust results and is suitable for screening.

• Klíčová slova
• ASA, CV, DEAE, DEAE-cellulose membrane, DUS, Diethylaminoethyl, Dry urinary samples, IPN, Isoforms, MLD, MS/MS, PTFE, Psap-d, S/N, SRM, Screening for metachromatic leukodystrophy, Tandem mass spectrometry, Urinary sulfatide, arylsulfatase A, coefficient of variation, dry urinary sample, isoform profile number (ratio of the sum of the major five isoforms and the C18:0 sulfatide), metachromatic leukodystrophy, polytetrafluoroethylene, prosaposin deficiency, selected reaction monitoring, signal to noise ratio, tandem mass spectrometry,
• MeSH
• DEAE-celulosa MeSH
• dítě MeSH
• extrakce na pevné fázi MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• membrány umělé MeSH
• metachromatická leukodystrofie diagnóza   moč   MeSH
• mladiství MeSH
• odběr biologického vzorku normy   MeSH
• předškolní dítě MeSH
• referenční standardy MeSH
• studie případů a kontrol MeSH
• sulfoglykosfingolipidy moč   MeSH
• tandemová hmotnostní spektrometrie MeSH
• vysoušení MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• DEAE-celulosa MeSH
• membrány umělé MeSH
• sulfoglykosfingolipidy MeSH