IMPROVED ACCURACY OF FATTY ACID TRACERETRACEE RATIO MEASURE GAS CHROMATOGRAPHY

稳定同位素示踪方法学在脂肪酸研究中的应用 动力学要求准确测量示踪比(TTR) 气相色谱/质谱仪(GC/MS)。当前的方法是 由于受日常工作的影响，TTR的测量有一定的局限性 仪器变异性和测量值上的样本量。我们 已经开发出一种新的方法来适应注意力 标准曲线方法中的依赖关系，以提高精度 棕榈酸甲酯Ttr测量的可重复性 用气相色谱-质谱法测定了一组样品中的血浆样品。 人体内注射了2H2-棕榈酸酯。当对样品进行分析时 在不同的场合，一种测量TTR值的传统方法 2H2-棕榈酸酯的日变异性为45%，日内变异性为 不同数量的样品的变异性约为10% 分析过了。新方法减少了这两个误差源，从而 获得的TTR值 在这两个场合的差异只有0.3%。我们的结论是 校正标准曲线内的浓度依赖偏差 该方法显著提高了甲基的准确度和重现性 手掌状TTR测量。因此，这种方法应该是 在使用稳定的同位素标记示踪剂评估时考虑 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.