L-DOPA storage glossary: terms used on the reagent stock card

Description

L-DOPA is catalogued under CAS 59-92-7, formula C9H11NO4, molar mass 197.19 g/mol. Because the molecule carries a catechol ring, the store treats it as an oxidation-sensitive solid and builds its whole handling routine around that single structural fact. The glossary below fixes the terms that appear on the stock card.

Registry number

CAS 59-92-7 — the identifier compared against the certificate of analysis at goods-in. Catalogue names such as levodopa or 3-hydroxy-L-tyrosine are cross-references to this number, not substitutes for it.

Molecular formula

C9H11NO4 — the basis for an independent recalculation of the mass printed on the label. A formula that does not reconcile with the catalogue mass is resolved with the supplier before the container is shelved.

Molar mass

197.19 g/mol — used to convert weighed portions into molar quantities in the consumption ledger, so that stock movements stay comparable across different pack sizes.

Catechol moiety

The ortho-dihydroxy fragment of the ring. It is the reason the material darkens on prolonged contact with air, especially under alkaline conditions, and the reason containers stay closed and shielded from light.

Discolouration

A visible browning of the solid. It is recorded as a storage observation, never as a verdict on identity; the lot goes for a repeat purity check before any decision on its further circulation.

Compatibility group

The shelf class derived from the classification section of the safety data sheet. An oxidation-sensitive amino acid derivative stands apart from oxidising agents, from strong acids and from alkaline reagents.

Working portion

A quantity transferred once from the primary container into a labelled secondary vessel carrying the parent lot number and the transfer date.

Transport file

The set of papers accompanying a consignment: transport note, copy of the certificate and copy of the safety data sheet, with outer marking taken from the classification.

Stock card

The document opened on the day of acceptance and closed at the final movement of the lot, holding every opening, every mass withdrawn and every relocation.

Two of these entries carry most of the practical weight. The catechol moiety explains why an amber or opaque container is not an ornament but a storage requirement, and the stock card explains how a measurement made today can still be traced to its material several years from now. See also our catalogue listing: ALCAR / Acetyl-L-Carnitine – Purity ≥ 99% net weig.

Periodic inspection closes the loop. The storekeeper compares declared mass with actual mass, looks for caking, colour change and seal damage, and books the result on the card. A lot that fails inspection leaves circulation under a written protocol rather than by quiet removal from the shelf. See also our reagent-grade material: Noopept / НООПЕПТ. Synthetic substance ≥ 99% 1000M.

Other catalogue items

• Noopept / НООПЕПТ. Synthetic substance ≥ 99% 1000MG.
• ALCAR / Acetyl-L-Carnitine – Purity ≥ 99% net weight 1000mg.
• HHC-O, 85% zawartości HHC-O w 1000mg!
• FL-MODAFINIL, 99% Czystości, 1000MG OR 1GRAM

Selected literature

Animal and in vitro studies indexed in PubMed; no human-use guidance is provided here.

• Klawans HL Levodopa-induced myoclonus 1975, Archives of neurology. PMID 1079721
• Nutt JG Levodopa: rational and irrational pharmacology 1994, Annals of neurology. PMID 8024259
• Nutt JG Pharmacokinetics and pharmacodynamics of levodopa 2008, Movement disorders : official journal of the. PMID 18781675
• Morris JG A review of some aspects of the pharmacology of levodopa 1978, Clinical and experimental neurology. PMID 386308

Scope of use. Any administration to humans is excluded. The material is not a veterinary product. It is a high-purity laboratory product for research using HPLC and GC-MS. Not a medicine, medical device or food product.