Laboratory of Toxicology, Department of Bioanalysis, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium.
Anal Chem. 2021 Feb 2;93(4):2660-2668. doi: 10.1021/acs.analchem.0c05018. Epub 2021 Jan 6.
Many populations in low- and middle income countries are at a higher risk of thiamine deficiency, mainly due to the lack of dietary diversification and their reliance on staple crops low in thiamine content, such as polished rice. Unfortunately, symptoms of thiamine deficiency are variable and clinical determination of thiamine status is essential for early diagnosis. Currently, the diagnosis of thiamine deficiency in remote regions is hampered due to several drawbacks related to venous blood collection, for example, cold chain transport. Therefore, we here describe the first liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of thiamine diphosphate (TDP) in dried blood, using volumetric absorptive microsampling (VAMS). Moreover, by setting up an additional method in liquid blood, the results in VAMS samples could be compared to liquid blood samples. Both methods, employing a simple one-step extraction and fast (2 min) chromatography, were fully validated based on international guidelines. Accuracy (% bias) was below 6.5% for all QC levels. The total imprecision (% CV) was below 13% for both QCs and native blood samples. The recovery of the VAMS samples was not impacted by the hematocrit, within the hematocrit range of 0.20-0.60. Additionally, we showed improved TDP stability in dried blood compared to liquid blood. VAMS samples were stable for 1 week at 60 °C or at high humidity (80%) and for at least 1 month at room temperature. Finally, we demonstrated the commutability of commercial calibrators with authentic blood samples. The validity and applicability of both methods were demonstrated via their successful application on blood samples from healthy volunteers.
许多中低收入国家的人群面临更高的硫胺素缺乏风险，主要是由于饮食单一，依赖硫胺素含量低的主食，如精米。不幸的是，硫胺素缺乏的症状是多变的，临床确定硫胺素状况对于早期诊断至关重要。目前，由于与静脉采血相关的一些缺陷，如冷链运输，远程地区的硫胺素缺乏症诊断受到阻碍。因此，我们在这里描述了第一种使用体积吸收微采样（VAMS）测定干血中硫胺素二磷酸（TDP）的液相色谱-串联质谱（LC-MS/MS）方法。此外，通过建立液体血液中的附加方法，可以将 VAMS 样本的结果与液体血液样本进行比较。两种方法均采用简单的一步提取和快速（2 分钟）色谱，根据国际指南进行了全面验证。所有 QC 水平的准确度（%偏差）均低于 6.5%。QC 和天然血液样本的总不精密度（%CV）均低于 13%。VAMS 样本的红细胞比容回收率在 0.20-0.60 范围内不受红细胞比容的影响。此外，与液体血液相比，我们证明了干血中的 TDP 稳定性有所提高。VAMS 样本在 60°C 或高湿度（80%）下可稳定保存 1 周，在室温下至少可稳定保存 1 个月。最后，我们证明了商业校准品与真实血液样本的互换性。两种方法都成功应用于健康志愿者的血液样本，证明了它们的有效性和适用性。
