The main objective of the present study is a quantitative determination of menthol using a simple, sensitive, and reproducible method of reacting menthol with an aromatic aldehyde (salicylaldehyde) in an acidic medium. A linear response was observed between the concentration and the absorbance in the range 0.02–3 mg/5 mL possessing a correlation coefficient greater than 0.999 and exhibiting good recovery values (99.54–100.40%). The wavelength of the maximum absorbance (λ_max) was measured at 498 nm immediately after the reaction and subsequently within 1 h. The proposed method was validated according to the ICH guidelines for parameters including linearity, precision, accuracy, range, stability, and robustness. Hence the developed method can be used in the analysis of menthol in drug formulations.

中文翻译：

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分光光度法测定薄荷醇的方法开发与验证

本研究的主要目的是使用一种简单，灵敏且可重现的方法，在酸性介质中使薄荷醇与芳香醛（水杨醛）反应，从而定量测定薄荷醇。浓度与吸光度之间在0.02–3 mg / 5 mL范围内观察到线性响应，相关系数大于0.999，并具有良好的回收率（99.54–100.40％）。反应后立即在1 h内在498 nm处测量最大吸光度（_λmax）的波长。根据ICH指南验证了所提出的方法的参数，包括线性，精度，准确性，范围，稳定性和鲁棒性。因此，开发的方法可用于药物制剂中薄荷醇的分析。