Dragendorff reagent (CAS 39775-75-2)

Dragendorff reagent, named after its developer Heinrich Dragendorff, is a chemical solution utilized in analytical chemistry to detect and identify alkaloids. Typically composed of bismuth salts like bismuth nitrate or bismuth subnitrate dissolved in an acidic solution, often acetic acid, it serves as a spray and plunge reagent for chromatography. This non-aqueous variant of the reagent, known as Thiess, Reuther, and Vagujfalvi, is employed in TLC (thin-layer chromatography) to detect alkaloids and other nitrogen compounds. When applied to a sample containing alkaloids, Dragendorff reagent induces characteristic precipitates or color changes, indicating the presence of alkaloids. This reaction relies on the ability of alkaloids to form complexes with bismuth ions, resulting in observable orange-red to brown precipitates or color changes that vary depending on the specific alkaloid and concentration. Widely utilized in forensic science, pharmaceutical analysis, and natural product chemistry, Dragendorff reagent offers a reliable and relatively straightforward method for the initial screening and identification of alkaloids across diverse samples. However, it′s to note that Dragendorff reagent lacks specificity for individual alkaloids, necessitating additional confirmatory tests for accurate identification.