{"id":35,"date":"2026-07-14T18:10:15","date_gmt":"2026-07-14T18:10:15","guid":{"rendered":"https:\/\/blitzlab.eu\/wissen-coa-lesen\/"},"modified":"2026-10-23T23:36:59","modified_gmt":"2026-10-23T21:36:59","slug":"reading-a-coa","status":"publish","type":"page","link":"https:\/\/blitzlab.eu\/en\/wissen-coa-lesen\/","title":{"rendered":"Understanding and reading a Certificate of Analysis (COA)"},"content":{"rendered":"<main class=\"container legal-wrap article\">\n  <div class=\"breadcrumb\"><a href=\"\/en\/\">Home<\/a><span class=\"sep\">\u203a<\/span><a href=\"\/en\/blog\/\">Blog<\/a><span class=\"sep\">\u203a<\/span><span>Read the COA<\/span><\/div>\n\n  <h1>Understanding and reading a Certificate of Analysis (COA)<\/h1>\n  <p class=\"legal-lead\">For research peptides, the COA is the most important document of trust. Here, we explain field by field what it contains \u2013 and how to distinguish a genuine certificate from a worthless one.<\/p>\n  <div class=\"legal-flag\"><svg class=\"bl-i\" width=\"16\" height=\"16\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.8\" stroke-linecap=\"round\" stroke-linejoin=\"round\" aria-hidden=\"true\" focusable=\"false\"><circle cx=\"12\" cy=\"12\" r=\"9\"\/><path d=\"M12 11v5\"\/><path d=\"M12 7.6h.01\"\/><\/svg> General, scientific, factual information. No health, dosage, or application advice. Research Use Only.<\/div>\n\n  <h2>What is a COA?<\/h2>\n  <p>One <strong>Certificate of Analysis<\/strong> English <em>Certificate of Analysis<\/em>, kurz COA) dokumentiert die Ergebnisse der Qualit\u00e4tspr\u00fcfung einer konkreten <strong>Production batch<\/strong>. It is not a general marketing document but batch-specific: every batch (lot) has its own COA with its own number. A COA is only meaningful when it has been issued by an <strong>independent third-party laboratory<\/strong> was created \u2013 not by the seller themselves.<\/p>\n\n  <h2>The key fields at a glance<\/h2>\n  <ul>\n    <li><strong>Product \/ Identity<\/strong> Peptide name, sequence if applicable, CAS number, and molecular formula.<\/li>\n    <li><strong>Batch number<\/strong> Unique identifier of the tested batch.<\/li>\n    <li><strong>Purity (HPLC):<\/strong> Percentage purity, typically stated as \"\u2265 99%\", determined by high-performance liquid chromatography.<\/li>\n    <li><strong>Identity \/ Molecular Mass (LC-MS):<\/strong> Confirmation that the measured mass corresponds to the expected molecular mass.<\/li>\n    <li><strong>Appearance<\/strong> e.g. \u201ewhite lyophilised powder\u201c \u2013 a simple visual plausibility check.<\/li>\n    <li><strong>Test Date &amp; Method<\/strong> When and by which procedures it was tested.<\/li>\n    <li><strong>Labour \/ Signature:<\/strong> Name of the testing laboratory or responsible person.<\/li>\n  <\/ul>\n\n  <h2>HPLC and LC-MS \u2013 a brief explanation<\/h2>\n  <p>The two central values stem from two procedures: <strong>HPLC<\/strong> mostly misses the <em>Purity<\/em> (what percentage of the sample is the target molecule), <strong>LC-MS<\/strong> confirms the <em>Identity<\/em> about the molecular mass. Together, they answer the two most important questions: \u201eIs it the right molecule?\u201c and \u201eHow pure is it?\u201c A detailed explanation can be found in the article <a href=\"\/en\/peptide-purity-hplc-ms\/\">Peptide Purity: HPLC and LC-MS Explained<\/a>.<\/p>\n\n  <h2>How to recognise a trustworthy COA<\/h2>\n  <ul>\n    <li><strong>Third-party lab<\/strong> The certificate comes from an independent laboratory, not from the seller's own production.<\/li>\n    <li><strong>Mentioned methods:<\/strong> HPLC and LC-MS are named explicitly \u2013 including the purity value and the measured mass.<\/li>\n    <li><strong>Readable &amp; complete:<\/strong> No cropped image, no generic template without a batch number.<\/li>\n  <\/ul>\n  <p><strong>Warning signs<\/strong> no COA at all; a \u201eCOA\u201c without a batch number; a document that is identical for all products; or a certificate that originates solely from the seller and does not specify a method.<\/p>\n\n  <h2>This is how BlitzLab handles COAs<\/h2>\n  <p>At BlitzLab, each batch is externally tested using HPLC and LC-MS; the batch-specific COA can be viewed on the respective product page. More about our quality and compliance framework can be found on the page <a href=\"\/en\/compliance\/\">Compliance \/ RUO<\/a>.<\/p>\n\n  <div class=\"article-cta\">\n    <div>\n      <strong>View batch with COA<\/strong>\n      <p>Every product shows its batch-specific Certificate of Analysis directly on the product page.<\/p>\n    <\/div>\n    <a href=\"\/en\/shop\/\" class=\"btn btn-blue\">Shop now <span>\u2192<\/span><\/a>\n  <\/div>\n\n  <div class=\"wiss-related\">\n    <h3>More on the blog<\/h3>\n    <ul>\n      <li><a href=\"\/en\/peptide-purity-hplc-ms\/\">Peptide Purity: HPLC and LC-MS Explained<\/a><\/li>\n      <li><a href=\"\/en\/spotting-a-reliable-supplier\/\">Identifying a Reputable Peptide Supplier: 7-Point Checklist<\/a><\/li>\n      <li><a href=\"\/en\/storage-and-handling\/\">Storing and Handling Research Peptides<\/a><\/li>\n    <\/ul>\n  <\/div>\n<\/main>","protected":false},"excerpt":{"rendered":"<p>Start&rsaquo;Blog&rsaquo;COA lesen Analysenzertifikat (COA) lesen und verstehen Das COA ist bei Forschungspeptiden das wichtigste Vertrauensdokument. Hier erkl\u00e4ren wir Feld f\u00fcr Feld, was darin steht \u2013 und woran man ein echtes von einem wertlosen Zertifikat unterscheidet. Allgemeine, wissenschaftlich-faktische Information. Keine Gesundheits-, Dosierungs- oder Anwendungsberatung. Research Use Only. Was ist ein COA? Ein Analysenzertifikat (englisch Certificate of [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-35","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blitzlab.eu\/en\/wp-json\/wp\/v2\/pages\/35","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blitzlab.eu\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blitzlab.eu\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blitzlab.eu\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blitzlab.eu\/en\/wp-json\/wp\/v2\/comments?post=35"}],"version-history":[{"count":2,"href":"https:\/\/blitzlab.eu\/en\/wp-json\/wp\/v2\/pages\/35\/revisions"}],"predecessor-version":[{"id":269,"href":"https:\/\/blitzlab.eu\/en\/wp-json\/wp\/v2\/pages\/35\/revisions\/269"}],"wp:attachment":[{"href":"https:\/\/blitzlab.eu\/en\/wp-json\/wp\/v2\/media?parent=35"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}