c) Abbreviation: AA = acetic anhydrides; HFBA
Abbreviations: AGE = advanced glycation end product, BAP = bone alkaline phosphatase, BMI = body mass index, DM = diabetes mellitus, ELISA = enzyme-linked immunosorbent assay, HbA1c = hemoglobin A1c, HFBA
= heptafluorobutyric acid, HP = hydroxylysylpyridinoline, HPLC = high-performance liquid chromatography, LP = lysylpyridinoline, OA = osteoarthritis, OCN = osteocalcin, PYD = pyridinium, RAGE = receptor for AGE, TKA = total knee arthroplasty, VA = Department of Veterans Affairs.
HFBA served as a counterion and was essential for the retention of PMP on the [C.
1] Nonstandard abbreviations: PN, pyridoxine; PNP, pyridoxine 5'-phosphate; PL, pyridoxal; PLP, pyridoxal 5'-phosphate; PM, pyridoxamine; PMP, pyridoxamine 5'-phosphate; PA, 4-pyridoxic acid; FMN, flavin mononucleotide; LC-MS /MS, liquid chromatography-tandem mass spectrometry; HFBA, heptafluorobutyric acid; TCA, trichloroacetic acid; MRM, multiple-reaction monitoring; LOD, limits) of detection; and S/N, signal-to-noise.
The mass spectral characteristics of the HFBA
derivatives have been described by Thurman et al.
46 cm Spherisorb C-18 column (Teknokroma) with a linear gradient of 90 mL/L to 180 mL/L acetonitrile over 1 mL/L HFBA
in 35 min, followed by a column cleaning step of 15 min with 900 mL/L acetonitrile in 1 mL/L HFBA