Question

Vincristine in ultraviolet spectrophotometry \(\lambda_{max}\) value.

• A. 217 nm
• B. 245 nm
• C. 290 nm
• D. 360 nm

Hint:

Always use the compound's known $\lambda_{max}$ for most accurate quantitative UV analysis, as this gives the highest molar absorptivity.

Answer 1

The Correct Option is C

Vincristine is a vinca alkaloid used in cancer chemotherapy and exhibits characteristic absorbance in the ultraviolet region due to its conjugated double bond system and aromatic rings. In UV-Visible spectrophotometry, the compound shows a maximum absorbance ($\lambda_{max}$) at around 290 nm, which corresponds to the $\pi \rightarrow \pi^*$ electronic transition.
This wavelength is significant for qualitative and quantitative analysis of vincristine in pharmaceutical preparations, as it allows sensitive and specific detection using UV spectroscopy.
Vincristine’s $\lambda_{max}$ value is a result of its molecular structure, including indole and catharanthine-like moieties that absorb in the UV range. UV absorbance at 290 nm ensures accurate monitoring during analytical and quality control procedures.