First detection of free d-amino acids in human nails by combination of derivatization and UPLC-ESI-TOF-MS

Development of the High Sensitive Separation Analysis Method of Metabolites in Human Nail and its Application to the Diagnosis of Chronic Disease

“…Thus, the simultaneous determination of DL-amino acids by UPLC-ESI-TOF-MS was attempted in this study. The derivatives of 17 DL-amino acids were well separated using both elution systems; i.e., the gradient elution with water-acetonitrile containing 0.1% FA, and the gradient elution with 5 mM ammonium acetate buffer 0.1% FA acetonitrile [5]. Fig.…”

“…According to recent reports, human nails may be used to obtain physiologic information, and may serve as a noninvasive bio sample for the diagnosis of chronic disease. Certain kinds of endogenous biogenic amino acids, polyamines and AGEs have been detected in the human nail [4][5][6][7][8].…”

“…In contrast, the human nail is relatively clean and the samples can be quickly and noninvasively collected and easily stored. Analyzing the components of nail provides an important means for determining the individual past history of long-term chemical exposures, because many substances have been detected in the nail [4][5][6][7][8]. Due to the stability of drugs in nails, many studies concerning nail analysis have dealt with drugs of abuse, such as cocaine, itraconazole and amphetamines [9,10].…”

Derivatization-based High-throughput Bioanalysis by LC-MS

“…Therefore, the determination using LC-MS/MS is recommended in such cases, although the derivatives are a fluorescent. [72][73][74][75][76] As an example, the analysis of the racemization and isomerization of N-terminal Asp in amyloid-β (Aβ) peptides in the brain homogenates of Alzheimer's disease (AD) patients were accomplished by (R)-DBD-PyNCS labeling and LC-MS/MS analysis ( Table 2). 77 The post-translational racemization and isomerization might induce the density and localization of plaque desposition in the brain tissue, because AD is related to the formation and aggregation of Aβ peptide plaques in the human brain.…”

Development of Benzofurazan−bearing Fluorescence Labeling Reagents for Separation and Detection in High−performance Liquid Chromatography

“…The determination of DL−amino acids in the human nail of diabetes patients (age: 40−82; 3 men and age: 58−76; 3 women) and healthy persons (age: 69−83; 3 men and age: 47−78; 2 women) was tried by UPLC−FL and UPLC−ESI−TOF−MS after derivatization with R ( )−DBD−PyNCS [78,79]. Although a long time was required for the separation of the amino acid mixture by the conventional HPLC system, the high−throughput separation is currently carried out using an ultra−high pressure HPLC system.…”