Kish-Trier E, Schwarz E L, Pasquali M, Yuzyuk T
ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT, United States.
Department of Pathology, University of Utah, Salt Lake City, UT, United States.
Clin Mass Spectrom. 2016 Dec 20;2:11-17. doi: 10.1016/j.clinms.2016.12.001. eCollection 2016 Dec.
Polyunsaturated fatty acids (PUFAs), including essential omega-3 and omega-6 fatty acids, play important roles in diverse physiological and pathological processes. Diligent monitoring of PUFAs is recommended for individuals with increased risk of developing essential fatty acid deficiency (EFAD), including premature and very low birth weight infants, patients on prolonged parenteral nutrition, and those with dietary restrictions, for example due to inborn errors of metabolism. Here, we present a gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS) method for the quantitation of total levels of twenty-two fatty acids (C12-C22) in serum/plasma, including omega-3 and omage-6 PUFAs. Hydrolysis was used to release esterified fatty acids, which were analyzed by GC-NCI-MS as pentafluorobenzyl esters in selected-ion monitoring (SIM) mode. The calibration curves for all analytes had consistent slopes with R of ⩾0.990. Intra- and inter-assay precision CVs were ⩽9.0% and ⩽13.2%, respectively. Samples were found to be stable for 24 h at room temperature, at least 7 days at 4 °C, at least 75 days at -20 °C, and for three freeze/thaw cycles. No matrix effects or interferences were observed. This method offers improvements over published studies including smaller sample volume, inclusion of additional internal standards, analysis in a single injection, and use of methane reagent gas. This method could be used in a clinical laboratory setting for the diagnosis of EFAD, evaluation of nutritional status, and diet monitoring.
多不饱和脂肪酸（PUFAs），包括必需的ω-3和ω-6脂肪酸，在多种生理和病理过程中发挥重要作用。对于有发生必需脂肪酸缺乏症（EFAD）风险增加的个体，建议进行PUFAs的严格监测，这些个体包括早产和极低出生体重的婴儿、接受长期肠外营养的患者以及那些有饮食限制的人，例如由于先天性代谢缺陷。在此，我们提出一种气相色谱-负化学电离-质谱（GC-NCI-MS）方法，用于定量血清/血浆中二十二种脂肪酸（C12-C22）的总水平，包括ω-3和ω-6多不饱和脂肪酸。水解用于释放酯化脂肪酸，通过GC-NCI-MS在选择离子监测（SIM）模式下将其作为五氟苄酯进行分析。所有分析物的校准曲线斜率一致，R⩾0.990。批内和批间精密度CV分别⩽9.0%和⩽13.2%。发现样品在室温下稳定24小时，在4°C至少稳定7天，在-20°C至少稳定75天，并且可进行三个冻融循环。未观察到基质效应或干扰。该方法相对于已发表的研究有改进，包括更小的样品体积、包含额外的内标、单次进样分析以及使用甲烷反应气。该方法可用于临床实验室环境中EFAD的诊断、营养状况评估和饮食监测。
