Background Stable carbon isotope analysis of sugars in honey by LC–isotope ratio mass spectrometry (IRMS) is a useful tool for detecting adulteration of honey with extraneous sugar. Purity criteria based on 13C/12C ratios of saccharides in honey, determined by LC–IRMS of a large number of authentic honey samples, have been elaborated. However, no interlaboratory comparison (ILC) has yet been performed to estimate the precision of the method under reproducibility conditions. Objective To address this knowledge gap an ILC involving 14 laboratories and using six honey samples was conducted. Methods The participants were allowed to use their LC–IRMS-based method of choice for sample preparation and compound separation. Results The precision figures were estimated according to ISO 5725:1994. The repeatability relative standard deviation (RSDr) for the determination of δ13C values of fructose and glucose varied between 0.3 and 0.5%, with 0.3 and 1.0% for disaccharides, and 0.7 and 2.8% for trisaccharides. The RSDR varied between 0.8 and 1.8% for the monosaccharides, 1.0 and 1.5% for disaccharides, and 1.4 and 2.8% for trisaccharides. Conclusion Based on the obtained precision data the LC–IRMS method for the determination of 13C/12C ratios of saccharides in honey was considered fit for the conformity assessment of honey with established purity criteria. Highlights Precision estimates for a LC–IRMS method to determine 13C/12C ratios of saccharides in honey were obtained through an ILC. The data created can form the basis for the standardization of the method by interested standards-developing organizations for use in official control.

中文翻译：

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液相色谱-同位素比率质谱法测定蜂蜜中糖类 13C/12C 比率的实验室间比较结果

背景 通过 LC-同位素比质谱法 (IRMS) 对蜂蜜中的糖进行稳定碳同位素分析是检测蜂蜜中掺入外来糖的有用工具。已经详细阐述了基于蜂蜜中糖类的 13C/12C 比率的纯度标准，该标准由大量真实蜂蜜样品的 LC-IRMS 确定。然而，尚未进行实验室间比较 (ILC) 来估计该方法在重现性条件下的精度。目的 为解决这一知识差距，开展了涉及 14 个实验室并使用 6 个蜂蜜样本的 ILC。方法 允许参与者使用他们选择的基于 LC-IRMS 的方法进行样品制备和化合物分离。结果 精度数据根据 ISO 5725:1994 估算。测定果糖和葡萄糖的 δ13C 值的重复性相对标准偏差 (RSDr) 在 0.3% 和 0.5% 之间变化，二糖为 0.3% 和 1.0%，三糖为 0.7% 和 2.8%。单糖的 RSDR 在 0.8% 和 1.8% 之间变化，二糖的 RSDR 在 1.0% 和 1.5% 之间，三糖的 RSDR 在 1.4% 和 2.8% 之间。结论 基于获得的精密数据，用于测定蜂蜜中糖类 13C/12C 比率的 LC-IRMS 方法被认为适合使用既定纯度标准对蜂蜜进行合格评定。通过 ILC 获得用于确定蜂蜜中糖类 13C/12C 比率的 LC-IRMS 方法的精确估计值。创建的数据可以为相关标准制定组织在官方控制中使用的方法标准化奠定基础。