TY - JOUR
T1 - The simultaneous determination of neurotensin and its major fragments by on-line trace enrichment HPLC
AU - Kilts, Clinton D.
AU - Knight, David L.
AU - Nemeroff, Charles B.
N1 - Funding Information:
This work was funded by U.S. Public Health Service grants MH-39967 and MH-39415 from the National Institute of Mental Health. The authors gratefully acknowledge the efforts of Gail Atwater and Barbara House in the preparation of this manuscript and the excellent technical assistance of Timothy Ely and Yuka Parker.
PY - 1996/8/9
Y1 - 1996/8/9
N2 - An HPLC assay using on-line cation exchange trace enrichment and acetonitrile gradient elution, ion pair reverse phase separation with electrochemical detection (EC) is described for the simultaneous determination of the tridecapeptide neurotensin (NT) and six of its fragments. Cyclic voltammetric analysis indicated that the oxidative electrochemical properties of NT and its fragments is not merely a function of the sum of its electroactive amino acids (i.e. tyrosine) but reflects the presence and association of other amino acids (e.g. the arginine-arginine pair at position 8-9). Using the described method, NT1-6, NT1-8, NT1-10, NT1-11, NT8-13, NT9-13 and NT1-13, were baseline resolved within 20 min with a limit of detection varying from 1 to 5 ng peptide/injection. Other structurally similar or quantitatively significant neuropeptides (e.g. substance P, somatostatin, bombesin) did not interfere. Initial application of this on-line trace enrichment HPLC-EC assay to the question of the molecular nature of NT in unprocessed human CSF indicated the predominance of NT1-13 with an apparent formation of NT1-8 and NT9-13 resulting from more vigorous sample preparation techniques. The improvements in assay specificity, signal-to-noise ratios, biomatrix compatibility and assayable sample volume compared to non-enrichment HPLC-EC are discussed.
AB - An HPLC assay using on-line cation exchange trace enrichment and acetonitrile gradient elution, ion pair reverse phase separation with electrochemical detection (EC) is described for the simultaneous determination of the tridecapeptide neurotensin (NT) and six of its fragments. Cyclic voltammetric analysis indicated that the oxidative electrochemical properties of NT and its fragments is not merely a function of the sum of its electroactive amino acids (i.e. tyrosine) but reflects the presence and association of other amino acids (e.g. the arginine-arginine pair at position 8-9). Using the described method, NT1-6, NT1-8, NT1-10, NT1-11, NT8-13, NT9-13 and NT1-13, were baseline resolved within 20 min with a limit of detection varying from 1 to 5 ng peptide/injection. Other structurally similar or quantitatively significant neuropeptides (e.g. substance P, somatostatin, bombesin) did not interfere. Initial application of this on-line trace enrichment HPLC-EC assay to the question of the molecular nature of NT in unprocessed human CSF indicated the predominance of NT1-13 with an apparent formation of NT1-8 and NT9-13 resulting from more vigorous sample preparation techniques. The improvements in assay specificity, signal-to-noise ratios, biomatrix compatibility and assayable sample volume compared to non-enrichment HPLC-EC are discussed.
KW - Electrochemistry
KW - High-performance liquid chromatography
KW - HPLC-EC
KW - On-line trace enrichment HPLC
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U2 - 10.1016/0024-3205(96)00389-X
DO - 10.1016/0024-3205(96)00389-X
M3 - Article
C2 - 8795702
AN - SCOPUS:0030576539
VL - 59
SP - 911
EP - 920
JO - Life Sciences
JF - Life Sciences
SN - 0024-3205
IS - 11
ER -