A novel and original application of salting-out assisted liquid-liquid extraction is presented. This technique was used to purify the final reaction products (quaternary ammonium salts) from unreacted components and by-products present in multiple excesses. The partition of two structurally related compounds as (2-aminoethyl)trimethylammonium salt (a labeling reagent) and a derivative of [2-(imidazoline-1-yl)ethyl]trimethylammonium salt (a final reaction product of N-acetylglucosamine labeling by (2-aminoethyl)trimethylammonium salt) between acetonitrile-rich and water-rich layers was monitored by hydrophilic interaction chromatography with electrospray ionization mass spectrometry. Despite the poor solubility of both highly polar substances in solutions containing a high concentration of acetonitrile, the main portion of the labeling reagent (72%) can be removed from the crude reaction mixture in the first extraction step using 95% acetonitrile/5% water as an extraction solvent. The purified final reaction product contained only 2% of the labeling reagent, and it was suitable for analysis by direct infusion mass spectrometry to confirm its identity. The capability of the suggested purification protocol to process small-volume highly salted reaction mixtures was also proven by analysis of saccharide mixture containing glucose, maltose, and maltotriose labeled by the positively charged tag.

• Publikační typ
• časopisecké články MeSH

In this work, we compare labeling by two negatively charged fluorescent labels, 8-aminopyrene-1,3,6-trisulfonic acid (APTS) and 8-(2-hydrazino-2-oxoethoxy)pyrene-1,3,6-trisulfonic acid (Cascade Blue hydrazide [CBH]). Effectiveness of the labeling chemistries were investigated by 4-hydroxybenzaldehyde and maltoheptaose followed by LC/UV-MS and CE/LIF analysis, respectively. The reaction yield of APTS labeling was determined to be only ∼10%. This is due to reduction of almost 90% of the analyte by sodium cyanoborohydride to alcohol, which cannot be further labeled via reductive amination. However, the CBH labeling provides ∼90% reaction yield based on the LC/UV-MS measurements. The significantly higher labeling yield was also confirmed by CE/LIF measurements. Finally, the more effective hydrazone formation technique of CBH was characterized and applied for N-linked glycan analysis by CE/LIF.

• MeSH
• aminace MeSH
• chromatografie kapalinová metody   MeSH
• elektroforéza kapilární metody   MeSH
• fluorescenční barviva chemie   MeSH
• hmotnostní spektrometrie metody   MeSH
• hydrazony chemie   MeSH
• oligosacharidy analýza   chemie   MeSH
• pyreny chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH