Sigma-Aldrich offers doxycycline in various grades, each with specific purity and quality control parameters. Check the Certificate of Analysis (CoA) accompanying each batch for precise details; these CoAs provide the most accurate information for your specific purchase. Generally, expect a minimum purity of 95% for most grades, determined by high-performance liquid chromatography (HPLC). This analysis measures the amount of doxycycline base present.
Impurities and Analysis
The CoA will list potential impurities, including degradation products and related substances. These are quantified using established methods like HPLC and potentially other techniques, like UV-Vis spectroscopy. The acceptable limits for these impurities vary depending on the intended application of the doxycycline and the grade purchased. For example, pharmaceutical-grade doxycycline will have much stricter limits compared to reagent-grade material. Always consult the appropriate pharmacopoeia (e. g., USP, EP) for detailed specifications relevant to your needs.
Grade Selection
Selecting the appropriate grade is critical. Sigma-Aldrich provides various grades suited for different uses: research, analytical, and potentially pharmaceutical production. The label clearly states the grade, allowing you to choose the correct specification for your purpose. Consider the intended application before purchasing and verify compatibility with your methods and regulations.
