IMPROVED ACCURACY OF FATTY ACID TRACERETRACEE RATIO MEASURE GAS CHROMATOGRAPHY

稳定同位素示踪法研究脂肪酸 动力学需要通过以下方法精确测量示踪剂示踪比（TTR）： 气相色谱/质谱联用（GC/MS）。 目前的办法 测量TTR有局限性，因为日常的影响， 仪器变异性和样品量对测量值的影响。 我们 开发了一种新的方法， 标准曲线方法内的依赖性，以提高准确度 棕榈酸甲酯TTR测量结果的可重复性 GC/MS。新的方法被应用于从一个 输注2 H2-棕榈酸酯的人类受试者。 当分析样品时 在不同的情况下，测量TTR的传统方法 2 H2-棕榈酸酯产生了45%的日间变异性， 不同样品量的变异性约为10% 分析了 新方法减少了这两种误差来源， 获得的TTR值 两次的差异仅为0.3%。 我们的结论是 校正标准曲线内的浓度依赖性偏倚 方法显着提高了甲基的准确性和重现性 棕榈酸酯TTR测量。 因此，这种方法应该是 当使用稳定的同位素标记示踪剂来评估 体内脂肪酸动力学。

The use of stable isotope tracer methodology to study fatty acid kinetics requires accurate measurement of tracertracee ratio (TTR) by gas chromatography/mass spectrometry (GC/MS). Current approaches for measuring TTR have limitations because of the influence of day-to-day instrument variability and sample quantity on measured values. We have developed a new approach which accommodates concentration dependencies within a standard curve approach to improve the accuracy and reproducibility of methyl palmitate TTR measurements made by GC/MS. The new approach was applied to plasma samples obtained from a human subject infused with 2H2-palmitate. When samples were analyzed on separate occasions, a conventional approach to measure the TTR of 2H2-palmitate produced a 45% day-to-day variability and a within-day variability of approximately 10% for different quantities of sample analyzed. The new approach decreased both sources of error such that the TTR values obtained on the t wo occasions differed by only 0.3%. We conclude that correcting for concentration dependency biases within a standard curve approach markedly improves the accuracy and reproducibility of methyl palmitate TTR measurements. Therefore, this approach should be considered when using stable isotopically labeled tracers to evaluate in vivo fatty acid kinetics.