Dietary fatty acids can be both beneficial and detrimental to human health depending on the degree and type of saturation. Healthcare providers and research scientists monitor the fatty acid content of human plasma and serum as an indicator of health status and diet. In addition, both the Centers for Disease Control & Prevention (CDC) and the National Institutes of Health – Office of Dietary Supplements are interested in circulating fatty acids (FAs) because they may be predictive of coronary heart disease. The National Institute of Standards and Technology (NIST) provides a wide variety of reference materials (RMs) and Standard Reference Materials® (SRM®s) including blood, serum, plasma, and urine with values assigned for analytes of clinical interest. NIST SRM 2378 Fatty Acids in Frozen Human Serum was introduced in 2015 to help validate methods used for the analysis of FAs in serum, and consists of three different pools of serum acquired from (1) healthy donors who had taken fish oil dietary supplements (at least 1000 mg per day) for at least one month (level 1 material), (2) healthy donors who had taken flaxseed oil dietary supplements (at least 1000 mg per day) for at least one month (level 2 material), and (3) healthy donors eating “normal” diets who had not taken dietary supplements containing fish or plant oils (level 3 material). The use of dietary supplements by donors provided SRMs with natural endogenous ranges of FAs at concentrations observed in human populations. Results from analyses using two methods at NIST, including one involving a novel microwave-assisted acid hydrolysis procedure, and one at the CDC are presented here. These results and their respective uncertainties were combined to yield certified values with expanded uncertainties for 12 FAs and reference values with expanded uncertainties for an additional 18 FAs.

膳食脂肪酸对人类健康既有益又有害，具体取决于饱和程度和类型。医疗保健提供者和研究科学家监测人体血浆和血清中的脂肪酸含量，作为健康状况和饮食的指标。此外，美国疾病控制与预防中心 (CDC) 和美国国立卫生研究院膳食补充剂办公室都对循环脂肪酸 (FA) 感兴趣，因为它们可能预测冠心病。美国国家标准与技术研究所 (NIST) 提供各种参考物质 (RM) 和标准参考物质® (SRM®)，包括血液、血清、血浆和尿液，并为临床感兴趣的分析物指定了值。 NIST SRM 2378 冷冻人血清中的脂肪酸于 2015 年推出，旨在帮助验证用于分析血清中 FA 的方法，由从 (1) 服用鱼油膳食补充剂的健康捐赠者（在每天至少 1000 毫克）至少一个月（1 级材料），(2) 服用亚麻籽油膳食补充剂（每天至少 1000 毫克）至少一个月（2 级材料）的健康捐赠者，以及（ 3) 吃“正常”饮食、未服用含有鱼或植物油的膳食补充剂的健康捐赠者（3 级材料）。捐赠者使用膳食补充剂为 SRM 提供了在人群中观察到的天然内源性 FA 浓度范围。本文介绍了 NIST 使用两种方法的分析结果，其中一种涉及新型微波辅助酸水解程序，另一种是 CDC 的方法。 这些结果及其各自的不确定性相结合，得出 12 个 FA 的不确定性扩大的认证值和另外 18 个 FA 的不确定性扩大的参考值。