Background and Aims The total concentration of copper (Cu) in wine cannot be routinely measured without relatively expensive equipment, reagents and/or without labour‐intensive sample pretreatment. The following research describes an approach for the colorimetric measurement of total Cu in wine utilising a spectrophotometer and relatively cheap reagents. Method and Results The proposed method is based on using bicinchoninic acid as the complexing chromophore for Cu. Copper was measured directly and rapidly in white wine, while a digestion of red wine was required. A key step for the analysis in the non‐digested white wine matrix was the addition of silver(I) to aid the dissociation of Cu in the wine from sulfide. For red and white wines, the limit of detection was 0.02 mg/L Cu, and the repeatability was 3 ± 1%. The accuracy of the method was assessed in terms of recovery experiments (102 ± 3%, n = 4), and also by comparing total Cu concentration in 84 wines determined by the colorimetric method with that obtained by inductively coupled plasma with optical emission spectroscopy (R2 = 0.95). Conclusions The colorimetric determination of total Cu was successfully optimised and validated in white and red wines. Significance of the Study The methodology will allow wineries and researchers to routinely measure total Cu concentration in wine with a spectrophotometer.

中文翻译：

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葡萄酒中铜的比色测定：总铜

背景和目的 如果没有相对昂贵的设备、试剂和/或没有劳动密集型样品预处理，就无法常规测量葡萄酒中铜 (Cu) 的总浓度。以下研究描述了一种使用分光光度计和相对便宜的试剂比色测量葡萄酒中总铜的方法。方法和结果 所提出的方法基于使用二辛可宁酸作为铜的络合发色团。在白葡萄酒中直接快速测量铜，而需要对红葡萄酒进行消解。在未消化的白葡萄酒基质中进行分析的一个关键步骤是添加银 (I) 以帮助葡萄酒中的 Cu 从硫化物中解离。对于红葡萄酒和白葡萄酒，检测限为 0.02 mg/L Cu，重复性为 3 ± 1%。该方法的准确性通过回收率实验 (102 ± 3%, n = 4) 以及将比色法测定的 84 种葡萄酒中的总铜浓度与电感耦合等离子体与光学发射光谱法测定的总铜浓度进行比较来评估（ R2 = 0.95）。结论 在白葡萄酒和红葡萄酒中成功优化和验证了总铜的比色测定。研究的意义 该方法将允许酿酒厂和研究人员使用分光光度计定期测量葡萄酒中的总铜浓度。结论 在白葡萄酒和红葡萄酒中成功优化和验证了总铜的比色测定。研究的意义 该方法将允许酿酒厂和研究人员使用分光光度计定期测量葡萄酒中的总铜浓度。结论 在白葡萄酒和红葡萄酒中成功优化和验证了总铜的比色测定。研究的意义 该方法将允许酿酒厂和研究人员使用分光光度计定期测量葡萄酒中的总铜浓度。