Routinely used in quantitative determination of various analytes, UV–vis spectroscopy is commonly taught in undergraduate chemistry laboratory courses. Because the technique measures the absorbance of light through the samples, losses from reflection and scattering by large molecules interfere with the measurement. To emphasize the importance of light scattering in UV–vis spectroscopy, a laboratory experiment is described that guides students to study the hydrolysis of starch by amylase as a function of temperature. The reducing sugar produced from the hydrolysis is determined by dinitrosalicylic colorimetric assay via two methods: UV–vis spectroscopy and a smartphone-based colorimetry, which is capable of quantifying the concentration of a chromogenic compound in an opaque sample. From this experiment, students can directly learn to measure the activity of amylase, use a smartphone to perform colorimetry, observe the effect of light scattering, and gain a better understanding of UV–vis spectroscopy.

中文翻译：

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淀粉酶活性的比色测量：使用智能手机提高准确性和效率

紫外可见光谱通常用于各种分析物的定量测定，通常在大学化学实验室课程中教授。由于该技术可测量通过样品的光的吸收率，因此大分子的反射和散射所造成的损耗会干扰测量。为了强调光散射在紫外可见光谱中的重要性，我们描述了一个实验室实验，该实验指导学生研究淀粉酶随温度的变化对淀粉的水解作用。水解产生的还原糖通过二硝基水杨酸比色法通过两种方法测定：紫外可见光谱法和基于智能手机的比色法，该比色法能够对不透明样品中发色化合物的浓度进行定量。从这个实验中