Nestlé Research, Société des Produits Nestlé, 1000 Lausanne, Switzerland.
Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, 04103 Leipzig, Germany.
Molecules. 2019 Jul 27;24(15):2730. doi: 10.3390/molecules24152730.
Early life exposure to folate has long lasting effects on development and health. Newborns obtain part of their folate from maternal milk. Studies on health effects of milk folate require rapid, affordable and reliable measurements in large numbers of samples from cohort studies. Recently, a competitive chemiluminescence assay for quantification of folate has become available for automated diagnostic measurement of folate in human serum or plasma. We tested if this method ("FOLA" from Siemens Healthcare) could also be used for human milk. To minimize interference and matrix effects, samples had to be skimmed, diluted seven times with demineralized water, and heated for 5 min at 90 °C. Folate could thus be measured in a linear range between 8.4 and 111.7 nM, with recoveries for the most relevant form, 5-methyltetrahydrofolate (5-MeTHF), of 96%-107%. Results were comparable to those with a recently validated Liquid Chromatography/Mass Spectrometry method (Y = 0.998X - 0.2; R = 0.807). The FOLA method was subsequently used for samples from the LIFE Child cohort in Germany, providing first data of breast milk folate in this country (range: 6.2-100.7 nM). This technique could indeed prove useful for large cohorts with multiple samplings.
生命早期暴露于叶酸对发育和健康有持久影响。新生儿从母乳中获得部分叶酸。研究母乳叶酸对健康的影响需要在大量队列研究样本中进行快速、经济和可靠的测量。最近，一种用于定量叶酸的竞争化学发光测定法已经可用于人类血清或血浆中叶酸的自动诊断测量。我们测试了这种方法（西门子医疗的“FOLA”）是否也可用于人乳。为了最大程度地减少干扰和基质效应，必须对样品进行脱脂，用去矿物质水稀释七倍，并在 90°C 下加热 5 分钟。因此，叶酸可以在 8.4 至 111.7 nM 的线性范围内进行测量，对于最相关的形式 5-甲基四氢叶酸（5-MeTHF），回收率为 96%-107%。结果与最近验证的液相色谱/质谱法（Y = 0.998X - 0.2；R = 0.807）相当。随后，该方法用于德国 LIFE 儿童队列的样本，首次提供了该国母乳叶酸的数据（范围：6.2-100.7 nM）。这种技术对于具有多次采样的大型队列确实非常有用。
