Zinc is an essential trace element in humans. Zinc deficiency can result in a range of serious medical conditions which include effects on growth and development, the immune system, the central nervous system, and the gastrointestinal system. Diagnosis of zinc deficiency is often precluded by the lack of a noninvasive and reliable biomarker. Zinc concentration in nail is considered an emerging biomarker of zinc status in humans. Whether zinc in nail accurately reflects zinc status is beyond the scope of the current study, but is an important research question. The development of a portable method to quickly assess zinc concentration from a single nail clipping could be a useful advance. In this study, single toenail clippings from 60 individuals living in Atlantic Canada were measured for zinc using a portable X-ray fluorescence (XRF) technique. These samples were obtained from the Atlantic PATH cohort, part of the largest chronic disease study ever performed in Canada. Each toenail clipping was measured using three 300 s trials with a mono-energetic portable XRF system. Results were then assessed using two different approaches to the XRF analysis: (1) factory-calibrated zinc concentrations were output from each trial, and (2) energy spectra were analyzed for the characteristic X-rays resulting from zinc. Following the measurement of zinc using the non-destructive portable XRF method, the same clippings were measured for zinc concentration using the “gold standard” technique of inductively coupled plasma-mass spectrometry (ICP-MS). A linear equation of best fit was determined for the relationship between average XRF output zinc concentration and ICP-MS zinc concentration, with a correlation coefficient r = 0.60. Similarly, a linear equation of best fit was found for the relationship between a normalized XRF energy spectrum zinc signal and ICP-MS zinc concentration, with a correlation coefficient r = 0.68. Individual ICP-MS zinc concentrations ranged from 32 μg/g to 140 μg/g, with a population average of 85 μg/g. The results of this study indicate that portable XRF is a sensitive method for the measurement of zinc in a single nail clipping, and provides a reasonable estimation of zinc concentration. Further method development is required before portable XRF be considered a routine alternative to ICP-MS for the assessment of zinc in nail clippings.

锌是人体必需的微量元素。缺锌会导致一系列严重的疾病，包括对生长发育、免疫系统、中枢神经系统和胃肠系统的影响。由于缺乏非侵入性和可靠的生物标志物，锌缺乏症的诊断通常被排除在外。指甲中的锌浓度被认为是人类锌状态的新兴生物标志物。指甲中的锌是否准确反映锌的状态超出了目前的研究范围，但却是一个重要的研究问题。开发一种从一次指甲剪中快速评估锌浓度的便携式方法可能是一个有用的进步。在这项研究中，使用便携式 X 射线荧光 (XRF) 技术测量了居住在加拿大大西洋地区的 60 个人的单趾甲剪下的锌含量。这些样本来自大西洋 PATH 队列，这是加拿大有史以来最大的慢性病研究的一部分。使用单能便携式 XRF 系统使用三个 300 秒的试验测量每个脚趾甲剪裁。然后使用两种不同的 XRF 分析方法评估结果：(1) 从每次试验中输出工厂校准的锌浓度，以及 (2) 分析由锌产生的特征 X 射线的能谱。在使用非破坏性便携式 XRF 方法测量锌之后，使用电感耦合等离子体质谱 (ICP-MS) 的“金标准”技术测量了相同剪报中的锌浓度。对于平均 XRF 输出锌浓度与 ICP-MS 锌浓度之间的关系，确定了最佳拟合的线性方程，相关系数 r = 0.60。同样，对于归一化 XRF 能谱锌信号与 ICP-MS 锌浓度之间的关系，找到了最佳拟合的线性方程，相关系数 r = 0.68。单个 ICP-MS 锌浓度范围为 32 μg/g 至 140 μg/g，总体平均值为 85 μg/g。这项研究的结果表明，便携式 XRF 是测量单次指甲剪中锌的灵敏方法，并提供了对锌浓度的合理估计。在将便携式 XRF 视为 ICP-MS 的常规替代品用于评估指甲剪中的锌之前，需要进一步开发方法。找到了归一化 XRF 能谱锌信号与 ICP-MS 锌浓度之间关系的最佳线性方程，相关系数 r = 0.68。单个 ICP-MS 锌浓度范围为 32 μg/g 至 140 μg/g，总体平均值为 85 μg/g。这项研究的结果表明，便携式 XRF 是测量单次指甲剪中锌的灵敏方法，并提供了对锌浓度的合理估计。在将便携式 XRF 视为 ICP-MS 的常规替代品用于评估指甲剪中的锌之前，需要进一步开发方法。找到了归一化 XRF 能谱锌信号与 ICP-MS 锌浓度之间关系的最佳线性方程，相关系数 r = 0.68。单个 ICP-MS 锌浓度范围为 32 μg/g 至 140 μg/g，总体平均值为 85 μg/g。这项研究的结果表明，便携式 XRF 是测量单次指甲剪中锌的灵敏方法，并提供了对锌浓度的合理估计。在将便携式 XRF 视为 ICP-MS 的常规替代品用于评估指甲剪中的锌之前，需要进一步开发方法。这项研究的结果表明，便携式 XRF 是测量单次指甲剪中锌的灵敏方法，并提供了对锌浓度的合理估计。在将便携式 XRF 视为 ICP-MS 的常规替代品用于评估指甲剪中的锌之前，需要进一步开发方法。这项研究的结果表明，便携式 XRF 是测量单次指甲剪中锌的灵敏方法，并提供了对锌浓度的合理估计。在将便携式 XRF 视为 ICP-MS 的常规替代品用于评估指甲剪中的锌之前，需要进一步开发方法。