2 3 naphthalene dialdehyde nda

All solvents used were HPLC grade unless otherwise stated. Sodium hydroxide (NaOH), sulfuric acid (H₂SO₄), sodium cyanide (NaCN), potassium dihydrogen phosphate (KH₂PO₄), and dibasic potassium phosphate (K₂HPO₄), were purchased from Fisher Scientific (Hanover Park, IL). 2,3-Naphthalene dialdehyde (NDA) was obtained from TCI America (Portland, OR). 2-aminoethane sulfonic acid (taurine) and sodium metaborate tetrahydrate (NaBO₂4H₂O) were purchased from Alfa Aesar (Ward Hill, MA). Tetra butyl ammonium sulfate (TBAS) and 2,3,4,5,6-pentaflorobenzyl bromide (PFB-Br) were purchased from Sigma-Aldrich (St. Louis, MO) and Alfa Aesar (Haverhill, MA), respectively.
Phosphate borate buffer (0.05 M; pH 8.5) and NaOH (10 and 100 mM) were prepared in deionized water. H₂SO₄ (2 M) was diluted with 3.89:5 mL v/v DI water and ethanol. PFB-Br (20 mM) was prepared in ethyl acetate while 10 mM TBAS was diluted with a saturated solution of sodium tetraborate decahydrate (pH 9.5). A stock solution of NaCN was obtained by diluting a 1.8 mM solution (in 10 mM NaOH) with 10 mM aqueous NaOH. An NDA (2 mM) stock solution was prepared in 0.05 M phosphate borate buffer and 40% methanol. A taurine (0.1 M) solution was prepared in phosphate borate buffer. Hydroxoaquocobinamide was obtained from Dr. Gerry Boss, MD (Department of Medicine, University of California, San Diego, La Jolla, USA).

All materials used were HPLC grade unless otherwise indicated. Sodium hydroxide, sulfuric acid, sodium cyanide, KH₂PO₄, K₂HPO₄, and NH₄OH were purchased from Fisher Scientific (Hanover Park, IL). 2,3-Naphthalene dialdehyde (NDA) was obtained from TCI America (Portland, OR). Taurine (2-aminoethane sulfonic acid) and NaBO₂·4H₂O were purchased from Alfa Aesar (Ward Hill, MA). NaSCN was purchased from Acros Organics (Morris Plains, NJ). Human serum albumin (HSA) and NaHS were purchased from Sigma-Aldrich (St. Louis, MO).
Phosphate (0.1 M)/borate (0.05 M) buffer and stock solutions of Sodium hydroxide (1 M), sulfuric acid (1 M), and NaSCN (1 mM) were prepared in deionized water. sodium cyanide standards and NaHS were obtained by dilution from 1.8 mM and 1 M stock solutions, respectively, with 10 mM NaOH. NH₄OH was prepared by diluting the original aqueous solution (29% by weight or 14.5 M) to 30 µM in deionized water. The NDA (2 mM) stock solution was prepared in phosphate/borate buffer and 40% methanol. A taurine (50 mM) solution was prepared in phosphate/borate buffer. A standard HSA solution was obtained by dissolving 3.3 mg of HSA per mL of deionized water.