{"id":532,"date":"2022-10-02T07:40:48","date_gmt":"2022-10-02T07:40:48","guid":{"rendered":"https:\/\/mebicar.pl\/sklep\/l-dopa-%e2%89%a5-99-pure-chemical-substance-without-fillers\/"},"modified":"2026-09-01T01:26:51","modified_gmt":"2026-09-01T01:26:51","slug":"l-dopa-2","status":"publish","type":"product","link":"https:\/\/mebicar.pl\/en\/sklep\/l-dopa-2\/","title":{"rendered":"L-DOPA 1 g \u2014 Intake, Control and Custody Protocol for the Reagent Store"},"content":{"rendered":"\n

Levodopa is an amino acid carrying a catechol ring, and that ring governs how the container is handled once it arrives. The sequence below is written as a store protocol rather than as a product description. See also our laboratory reagent: Fenyloalanina \/ L-Phenylalanine \u2265 99% 1000mg<\/a>.<\/p>\n\n\n\n

Step one: intake of the container<\/h2>\n\n\n\n
  1. Compare the label against the order: registry number 59-92-7, formula C9H11NO4, molar mass 197.19, net mass 1 g.<\/li>
  2. Confirm that the certificate of analysis in the box carries the same batch number as the jar, and reject the delivery if it does not.<\/li>
  3. Record appearance in the intake note; the material is described as a white crystalline solid, and any yellow or grey cast is written down before the jar is stored.<\/li>
  4. Enter the batch into the reagent register with the delivery date, the retest date and the shelf location.<\/li>
  5. File the safety data sheet in its current version alongside the certificate.<\/li><\/ol>\n\n\n\n

    The appearance check is not cosmetic: a catechol is oxidation-prone, and darkening is the visible end of a process that has already changed the material. See also our catalogue listing: ALCAR \/ Acetyl-L-Carnitine – Purity \u2265 99% net weig<\/a>.<\/p>\n\n\n\n

    Step two: control before release to a method<\/h2>\n\n\n\n
    1. Read which method produced the assay figure on the certificate, and whether the figure is chromatographic or titrimetric.<\/li>
    2. Check that optical purity is addressed, either by specific rotation or by a chiral chromatographic determination, since the D form is a distinct article.<\/li>
    3. Confirm that water content is reported separately from the assay.<\/li>
    4. Confirm that residual solvents were tested against the manufacturing route rather than a generic list.<\/li>
    5. Only then release the batch and note the release in the register with a signature.<\/li><\/ol>\n\n\n\n

      Optical purity deserves the second position on that list. The two enantiomers share a formula, a mass and an ultraviolet spectrum, so a routine assay cannot separate them; only a chiral method or a polarimetric measurement can. A lot released without that line on the certificate is released on an assumption.<\/p>\n\n\n\n

      Step three: storage and each subsequent opening<\/h2>\n\n\n\n
      1. Store cool, dry and dark, in the original tightly closed container.<\/li>
      2. Equilibrate a cold container to room temperature before opening, so that condensation does not settle on the crystals.<\/li>
      3. Weigh promptly, reclose immediately and return the jar to its shelf position rather than leaving it on the bench.<\/li>
      4. Note date, mass taken and the person taking it, one line per withdrawal.<\/li>
      5. Inspect the remaining material at every opening and stop using the batch if the colour has shifted.<\/li><\/ol>\n\n\n\n

        Water solubility is limited here, so working solutions are prepared fresh, and any solution that develops colour on standing is discarded rather than filtered: the colour is the reaction product itself.<\/p>\n\n\n\n

        Step four: closing the batch<\/h2>\n\n\n\n
        1. Record the final withdrawal and the residual mass.<\/li>
        2. Dispose of the remainder through the chemical waste route, never through the sink.<\/li>
        3. Keep the certificate, chromatograms and register entries after the jar is gone, for as long as the results derived from it are in use.<\/li><\/ol>\n\n\n\n

          Other catalogue items<\/h2>\n\n\n\n