Goodwin John M, Kuiper Heather C, Brister Barrett, Vesper Hubert W
Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA.
J Mass Spectrom Adv Clin Lab. 2024 Aug 5;33:22-30. doi: 10.1016/j.jmsacl.2024.07.002. eCollection 2024 Aug.
Internal standards correct for measurement variation due to sample loss. Isotope labeled analytes are ideal internal standards for the measurement of fatty acids in human plasma but are not always readily available. For this reason, quantification of multiple analytes at once is most often done using only a single or few internal standards. The magnitude of the impact this has on method accuracy and precision is not well studied for gas chromatography-mass spectrometry systems.
This study aims to estimate bias and changes in uncertainty associated with using alternative fatty acid isotopologue internal standards for the estimation of similar or dissimilar long chain fatty acids.
Using a previously reported method for the quantification of 27 fatty acids in human plasma using 18 internal standards we obtained estimates of bias and uncertainty at up to three levels of fatty acid concentration.
With some notable exceptions, method accuracy remained relatively stable when using an alternative internal standard (Median Relative Absolute Percent Bias: 1.76%, Median Spike-Recovery Absolute Percent Bias: 8.82%), with larger changes in method precision (Median Increase in Variance: 141%). Additionally, the degree of difference between analyte and internal standard structure was related to the magnitude of bias and uncertainty of the measurement.
The data presented here show that the choice of internal standard used to estimate fatty acid concentration can affect the accuracy and reliability of measurement results and, therefore, needs to be assessed carefully when developing analytical methods for the measurement of fatty acid profiles.Disclaimer: The findings and conclusions in this report are those of the author(s) and do not necessarily represent the official position of the Centers for Disease Control and Prevention/the Agency for Toxic Substances and Disease Registry. Use of trade names is for identification only and does not imply endorsement by the Centers for Disease Control and Prevention, the Public Health Service, and the US Department of Health and Human Services.
内标可校正因样品损失导致的测量偏差。同位素标记的分析物是测定人血浆中脂肪酸的理想内标，但并非总能轻易获得。因此，一次对多种分析物进行定量时，最常仅使用一种或几种内标。对于气相色谱 - 质谱系统，其对方法准确性和精密度的影响程度尚未得到充分研究。
本研究旨在评估使用替代脂肪酸同位素内标物估算相似或不同长链脂肪酸时的偏差及不确定度变化。
采用先前报道的使用18种内标物定量人血浆中27种脂肪酸的方法，我们在高达三个脂肪酸浓度水平下获得了偏差和不确定度的估计值。
除了一些显著的例外情况，使用替代内标时方法准确性保持相对稳定（中位相对绝对百分比偏差：1.76%，中位加标回收率绝对百分比偏差：8.82%），但方法精密度变化较大（方差中位增加：141%）。此外，分析物与内标物结构之间的差异程度与测量的偏差和不确定度大小相关。
此处呈现的数据表明，用于估算脂肪酸浓度的内标物选择会影响测量结果的准确性和可靠性，因此，在开发脂肪酸谱测量分析方法时需要仔细评估。免责声明：本报告中的研究结果和结论为作者所有，不一定代表疾病控制与预防中心/有毒物质与疾病登记署的官方立场。使用商品名仅用于识别，并不意味着得到疾病控制与预防中心、公共卫生服务部和美国卫生与公众服务部的认可。
