Description

L-Thyroxine-[L-Tyr-Ring-13C6] Hydrochloride is a stable isotope-labeled analog of the thyroid hormone thyroxine, specifically enriched with carbon-13 on the tyrosine ring. This compound is essential as a high-purity internal standard for the precise quantification of thyroxine in complex biological matrices using mass spectrometry. It is primarily required by pharmaceutical R&D laboratories, clinical research organizations, and diagnostic manufacturers engaged in advanced hormone analysis, method development, and quality control.

Application

• Internal Standard for LC-MS/MS: Critical for accurate and reliable quantification of endogenous L-thyroxine (T4) in pharmacokinetic, bioequivalence, and clinical studies.
• Metabolic Pathway Research: Used as a tracer to investigate thyroid hormone metabolism, biosynthesis, and degradation pathways in vitro and in vivo.
• Diagnostic Assay Development: Serves as a reference material in the calibration and validation of high-sensitivity immunoassays and mass spectrometry-based clinical diagnostic tests.
• Pharmaceutical Impurity Profiling: Employed in the analysis and characterization of thyroxine-containing drug products to ensure purity and stability.
• Forensic & Doping Control Analysis: Facilitates the unambiguous identification and measurement of thyroid hormones in forensic toxicology and anti-doping programs.
• Quality Control & Method Validation: Provides a definitive standard for ensuring the accuracy, precision, and reproducibility of analytical methods in GLP/GMP environments.

Basic Information

Product Name	L-Thyroxine-[L-Tyr-Ring-13C6] Hydrochloride
CAS No.	720710-30-5
Molecular Formula	C15H1113C6I4NO4 • HCl
Molecular Weight	~841.8 g/mol (for 13C6 labeled form)
Synonyms	L-Thyroxine-[Tyrosine-Ring-13C6] Hydrochloride; T4-[L-Tyr-Ring-13C6] HCl; Levothyroxine-[L-Tyr-Ring-13C6] Hydrochloride; 3,5,3',5'-Tetraiodo-L-thyronine-[L-Tyr-Ring-13C6] Hydrochloride; (2S)-2-Amino-3-[4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl]propanoic-13C6 Hydrochloride; Stable Isotope Labeled Thyroxine HCl; 13C6-L-T4 HCl
EINECS	Contact for details

Quality Control

Our L-Thyroxine-[L-Tyr-Ring-13C6] Hydrochloride is manufactured under controlled conditions to ensure the highest standards of isotopic and chemical purity. Each batch is subjected to rigorous analytical testing, including NMR and mass spectrometry for isotopic enrichment verification, and HPLC for chemical purity assessment. Certificates of Analysis (COA) are provided, detailing the isotopic purity (typically >99 atom % 13C), chemical purity (by HPLC), and other critical parameters to support your regulatory and research requirements.

Storage

Preserve in a tightly closed container, protected from light. Store at -20°C or below under an inert atmosphere for long-term stability. This product is hygroscopic (moisture-sensitive) and light-sensitive. Allow the sealed vial to equilibrate to room temperature before opening to minimize moisture uptake.

Specification

Item	Specification
Appearance	White to off-white powder
Identification (NMR)	Conforms to structure
Isotopic Purity (13C)	≥99 atom %
Chemical Purity (HPLC)	≥98.0%
Specific Rotation	Contact for details
Water Content (KF)	≤1.0%
Residual Solvents (GC)	Meets ICH guidelines

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.