title: Preconcentration of 3-nitrotyrosine in urine by transient isotachophoresis in MEKC.
abstract: Transient isotachophoresis (tITP), usually performed in CZE, is a useful on-line sample preconcentration technique for high saline samples. However, only a few papers have applied tITP in MEKC especially SDS system. This study compared tITP in MEKC with that in CZE for 3-nitro-tyrosine (NT) analysis in urine. No sample clean-up was required. Self-stacking occurred simultaneously as chloride in urine acted as a leading ion. HEPES-Tris buffer at pH 8.2 was used as a terminating electrolyte and separation buffer. UV detection wavelength was set at 426 nm. Experiments showed that tITP in MEKC exhibited much higher peak efficiency (up to 1000,000), and improved 4-fold sensitivity, compared with those by tITP in CZE. The limit of detection was 0.07 μM for 3-nitrotyrosine in urine.
authors: Key Laboratory of Chemistry of Northwestern Plant Resources, CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors: Haixia
authors: H
authors: Ren
authors: Xia
authors: X
authors: Liu
authors: Shengxiang
authors: S
authors: Jiang
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D057625:Isotachophoresis / Q000379:methods*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000652:urine
chemical_list: C002744:3-nitrotyrosine; D014443:Tyrosine