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Article
A Dual Functional-Group Derivatization Liquid Chromatography–Tandem Mass Spectrometry Method: Application for Quantification of Human Insulin
Recently, we developed a sensitive and accurate quantification method for short-chain peptides using dual functional-group derivatization. Sensitive and accurate quantification was achieved in our study by sep...
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Article
Development of certified reference material NMIJ CRM 6205-a for the validation of DNA quantification methods: accurate mass concentrations of 600-bp DNA solutions having artificial sequences
Two 600-bp DNA solutions (DNA600-G and DNA600-T) were developed as certified reference material, NMIJ CRM 6205-a, for the validation of DNA quantification methods. Both DNA600-G and DNA600-T are ideal as “spik...
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Protocol
Amino Acid Analysis by Hydrophilic Interaction Chromatography Coupled with Isotope Dilution Mass Spectrometry
Here, we describe an amino acid analysis that is based on the use of hydrophilic interaction liquid chromatography coupled with isotope dilution mass spectrometry for the accurate quantification of underivatiz...
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Article
Effects of the pH and Concentration on the Stability of Standard Solutions of Proteinogenic Amino Acid Mixtures
To prepare metrologically traceable amino acid mixed standard solutions, it is necessary to determine the stability of each amino acid present in the mixed solutions. In the present study, we prepared amino ac...
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Article
Concentration Measurement of Amino Acid in Aqueous Solution by Quantitative 1H NMR Spectroscopy with Internal Standard Method
We describe a procedure to determine concentrations of amino acid standard solutions by quantitative NMR spectroscopy using an internal standard. The measurement samples were prepared by solvent exchange to re...
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Article
High transport efficiency of nanoparticles through a total-consumption sample introduction system and its beneficial application for particle size evaluation in single-particle ICP-MS
In order to facilitate reliable and efficient determination of both the particle number concentration (PNC) and the size of nanoparticles (NPs) by single-particle ICP-MS (spICP-MS) without the need to correct ...
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Article
Open AccessPrenatal sonographic diagnosis of fetal valproate syndrome: a case report
Prenatal exposure of mother to valproate (VPA) causes teratogenic effects in the fetus, namely fetal valproate syndrome (FVS). We report a case of fetal valproate syndrome rarely diagnosed by prenatal sonograp...
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Article
Difference between Consensus Value of Participants' Results and Isotope-Dilution Mass Spectrometric Results in Proficiency Testing for Pesticide Residues in Husked Wheat
Proficiency testing was organized by the National Metrology Institute of Japan (NMIJ) as a measure of analytical competency in the quantification of pesticide residues in husked wheat powder. Seventy-one parti...
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Article
Development of High-purity Certified Reference Materials for 17 Proteinogenic Amino Acids by Traceable Titration Methods
To ensure the reliability of amino acid analyses, the National Metrology Institute of Japan of the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) has developed high-purity certifi...
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Article
Development of C-reactive protein certified reference material NMIJ CRM 6201-b: optimization of a hydrolysis process to improve the accuracy of amino acid analysis
To standardize C-reactive protein (CRP) assays, the National Metrology Institute of Japan (NMIJ) has developed a C-reactive protein solution certified reference material, CRM 6201-b, which is intended for use ...
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Article
Development and co-validation of porcine insulin certified reference material by high-performance liquid chromatography–isotope dilution mass spectrometry
This article concerns the development and co-validation of a porcine insulin (pINS) certified reference material (CRM) produced by the National Institute of Metrology, People’s Republic of China. Each CRM unit...
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Article
Evaluation of the performance of 57 Japanese participating laboratories by two types of z-scores in proficiency test for the quantification of pesticide residues in brown rice
A proficiency test for the analysis of pesticide residues in brown rice was carried out to support upgrading in analytical skills of participant laboratories. Brown rice containing three target pesticides (eto...
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Article
HPLC for Separation and Quantification of Deoxyribonucleic Acid Fragments and Measurement of Deoxyribonucleic Acid Degradation
DNA quantification has made its mark in pharmaceutical analysis and the life sciences. In particular, in the quality control of nucleic acid drugs and the detection and quantification of genetically modified o...
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Article
Quantitative NMR spectroscopy for accurate purity determination of amino acids, and uncertainty evaluation for different signals
Purity evaluation of amino acids using nuclear magnetic resonance spectroscopy is reported. Three amino acids (aspartic acid, valine, and arginine) and certified reference materials (CRMs), such as acidic, neu...
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Article
A Certified Urea Reference Material (NMIJ CRM 6006-a) as a Reliable Calibrant for the Elemental Analyses of Amino Acids and Food Samples
We examined the reliability of a certified reference material (CRM) for urea (NMIJ CRM 6006-a) as a calibrant for N, C, and H in elemental analyzers. Only the N content for this CRM is provided as an indicativ...
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Article
Time-resolved ICP-MS Measurement: a New Method for Elemental and Multiparametric Analysis of Single Cells
Time-resolved inductively coupled plasma mass spectrometry (ICP-MS) has attracted much attention for elemental and multiparametric analysis of single cells, instead of a classical bulk analysis of large amount...
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Article
Determination of the Carbon, Hydrogen and Nitrogen Contents of Alanine and Their Uncertainties Using the Certified Reference Material L-Alanine (NMIJ CRM 6011-a)
The carbon, hydrogen, and nitrogen (CHN) contents of alanine and their uncertainties were estimated using a CHN analyzer and the certified reference material (CRM) L-alanine. The CHN contents and their uncerta...
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Article
Comparison of three amino acid analysis methods and their application to the amino acid impurity analysis for the development of high-purity amino acid certified reference materials
The determination of amino acid (AA) impurity is important for the development of AA high-purity certified reference materials (CRMs), which play a key role in metrological traceability. We performed three ana...
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Article
High Sensitive Elemental Analysis of Single Yeast Cells (Saccharomyces cerevisiae) by Time-Resolved Inductively-Coupled Plasma Mass Spectrometry Using a High Efficiency Cell Introduction System
Trace elemental analysis of single yeast cells with time-resolved inductively coupled plasma mass spectrometry (ICP-MS) was successfully carried out, where a high efficiency cell introduction system (HECIS) co...
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Article
Clonality analysis suggests that STK11 gene mutations are involved in progression of lobular endocervical glandular hyperplasia (LEGH) to minimal deviation adenocarcinoma (MDA)
Lobular endocervical glandular hyperplasia (LEGH) is a benign proliferative disease of cervical glands. Although histological resemblance of minimal deviation adenocarcinoma (MDA) to LEGH and frequent associat...
