Milk is a homogeneous mixture of substances such as lactose, proteins, and glycerides. Among carbohydrates, lactose is a disaccharide composed of glucose and galactose, and it is present in bovine milk at a level of 4.6%. According to resolution no. 135 of the National Health Surveillance Agency (ANVISA) from Brazil, dairy products labeled “lactose-free” must contain 1.0 mg mL⁻¹ or less of this disaccharide. Thus, this work aims to develop and validate a method for quantifying the lactose content by quantitative nuclear magnetic resonance without the use of deuterated solvent (No-D qMNR). The validation of the developed method followed the norms provided by ANVISA resolution RDC no. 166, based on the figures of merit such as selectivity, linearity, the limit of detection (LOD) and quantification (LOQ), accuracy, precision, and robustness. The obtained results validated the method due to excellent linearity, demonstrated by the value of R > 0.990 and the homoscedasticity of the results, as well as precision, accuracy, and robustness values lower than 5%. Furthermore, LOD and LOQ values around 0.1345 mg mL⁻¹ and 0.4076 mg mL⁻¹, respectively, were obtained, which are lower than those required by legislation. The No-D qNMR technique was also able to quantify lactose content in commercial lactose-free milk.

中文翻译：

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在没有氘化溶剂的情况下，通过核磁共振对牛乳中的乳糖进行定量（No-D qNMR）。

牛奶是乳糖，蛋白质和甘油酯等物质的均质混合物。在碳水化合物中，乳糖是由葡萄糖和半乳糖组成的二糖，在牛乳中的含量为4.6％。根据决议号。来自巴西国家卫生监督局（ANVISA）135的标签，标有“无乳糖”的乳制品必须含有1.0 mg mL ^-1或更少的这种二糖。因此，这项工作旨在开发和验证一种无需使用氘化溶剂（No-D qMNR）即可通过定量核磁共振定量乳糖含量的方法。所开发方法的验证遵循ANVISA决议RDC no.2提供的规范。166，基于品质因数，例如选择性，线性，检测极限（LOD）和定量（LOQ），准确性，精度和鲁棒性。所获得的结果由于具有出色的线性度而得到了验证，该线性度通过R > 0.990的值和结果的均方差性以及低于5％的精度，准确性和鲁棒性值证明。此外，LOD和LOQ值分别约为0.1345 mg mL ^-1和0.4076 mg mL ^-1分别获得了低于立法要求的水平。No-D qNMR技术还能够定量市售无乳糖牛奶中的乳糖含量。