Pular para o conteúdo
Merck
  • Development of a Fully-automated On-line Oxidation Column-switching HPLC System for the Determination of Endogenous Melatonin in Human Clinical Samples.

Development of a Fully-automated On-line Oxidation Column-switching HPLC System for the Determination of Endogenous Melatonin in Human Clinical Samples.

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry (2015-11-13)
Tsubasa Oyama, Rie Nagai, Mayumi Fujimoto, Ryoko Konishi, Masashi Mita, Keiko Uezono, Kiyoshi Zaitsu, Kenji Hamase
RESUMO

A fully-automated on-line oxidation column-switching HPLC system has been developed for the determination of endogenous melatonin in human plasma and saliva. This HPLC system consists of four processes. In the first step, melatonin is fractionated using a reversed-phase C4 column (Proteonavi, 75 mm × 1.0 mm i.d.). In the second step, the obtained melatonin fraction is on-line collected, and oxidized to a highly-fluorescent compound, N-[(6-methoxy-4-oxo-1,4-dihydroquinolin-3-yl)methyl]acetamide (6-MOQMA), by mixing with hydrogen peroxide under alkaline conditions. In the third step, the produced 6-MOQMA is concentrated, and the oxidation reagents are removed using an alkaline resistive reversed-phase column, Asahipak ODP (35 mm × 1.0 mm i.d.). In the final fourth step, the 6-MOQMA is determined by a microbore-ODS column packed with ultrafine particles (CAPCELL PAK C18 IF, 250 mm × 1.0 mm i.d.). The limit of detection of melatonin using this system is about 200 amol/injection, and the determination of endogenous melatonin in a small volume of human physiological fluids, such as 100 μL of plasma and 300 μL of saliva, was successfully accomplished.

MATERIAIS
Número do produto
Marca
Descrição do produto

Sigma-Aldrich
Álcool etílico, puro, 200 proof, for molecular biology
Sigma-Aldrich
Ácido trifluoracético, ReagentPlus®, 99%
Sigma-Aldrich
Metanol, ACS reagent, ≥99.8%
Sigma-Aldrich
Álcool etílico, puro, 200 proof, ACS reagent, ≥99.5%
Sigma-Aldrich
Álcool etílico, puro, 200 proof, HPLC/spectrophotometric grade
Sigma-Aldrich
Tetra-hidrofurano, contains 250 ppm BHT as inhibitor, ACS reagent, ≥99.0%
Sigma-Aldrich
Carbonato de sódio, powder, ≥99.5%, ACS reagent
Sigma-Aldrich
Álcool etílico, puro, 200 proof, meets USP testing specifications
Sigma-Aldrich
Ácido trifluoracético, puriss. p.a., suitable for HPLC, ≥99.0% (GC)
Sigma-Aldrich
Acetonitrilo, ACS reagent, ≥99.5%
Sigma-Aldrich
Carbonato de sódio, ACS reagent, anhydrous, ≥99.5%, powder or granules
Sigma-Aldrich
Álcool etílico, puro, 190 proof, for molecular biology
Sigma-Aldrich
Metanol, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥99.8% (GC)
Sigma-Aldrich
Metanol, Laboratory Reagent, ≥99.6%
Sigma-Aldrich
Carbonato de sódio, ACS reagent (primary standard), anhydrous, 99.95-100.05% dry basis
Sigma-Aldrich
Etanol, ACS reagent, prima fine spirit, without additive, F15 o1
Sigma-Aldrich
Melatonina, powder, ≥98% (TLC)
Sigma-Aldrich
Ácido trifluoracético, ≥99%, for protein sequencing
Sigma-Aldrich
Carbonato de sódio, ReagentPlus®, ≥99.5%
Sigma-Aldrich
Etanol, purum, absolute ethanol, denaturated with 4.8% isopropanol, A15 IPA1, ≥99.8% (based on denaturant-free substance)
Sigma-Aldrich
Acetonitrilo, anhydrous, 99.8%
Sigma-Aldrich
Metanol, Absolute - Acetone free
Sigma-Aldrich
Metanol, ACS spectrophotometric grade, ≥99.9%
Sigma-Aldrich
Tetra-hidrofurano, ReagentPlus®, ≥99.0%, contains 250 ppm BHT as inhibitor
Sigma-Aldrich
Tetra-hidrofurano, contains 250 ppm BHT as inhibitor, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥99.9%
Sigma-Aldrich
Metanol, BioReagent, ≥99.93%
Sigma-Aldrich
Metanol, ACS reagent, ≥99.8%
Sigma-Aldrich
Álcool etílico, puro, 200 proof, anhydrous, ≥99.5%
Sigma-Aldrich
Peróxido de hidrogênio, contains ~200 ppm acetanilide as stabilizer, 3 wt. % in H2O
Sigma-Aldrich
Tetra-hidrofurano, anhydrous, ≥99.9%, inhibitor-free