Background: Phenylalanine is a significant biomarker for various diseases like phenylketonuria, gastric cancers, and ischemic stroke according to recent studies.

Method: In the present study; a simple, sensitive, selective and novel analytical method was validated by using an ultrafiltration-based extraction and LC-MS/MS quantification of phenylalanine in human plasma using ¹³C phenylalanine heavy isotope. Amicon® Ultra Centrifugal Filter was used for ultrafiltration. Parameters affecting LC separation and MS/MS detection were investigated and optimized. Chromatographic separation was achieved on a Merck SeQuant ZIC-HILIC (100x4.6 mm, 5 μm) at a column temperature of 40°C using a mobile phase of mixture of acetonitrile containing 0.1% formic acid and water containing 0.1% formic acid (50:50 v/v) at a flow rate of 0.35 mL/min. The transitions m/z 167→121 for ¹³C phenylalanine, m/z 166→120 for phenylalanine itself were monitored using the MRM mode.

Result: The assay was linear concentration range of 0.0025 μg/mL to 1.20 μg/mL (R²=0.999). The developed method was validated according to FDA guidelines. The method was found linear, sensitive, precise, accurate, and selective.

背景：根据最近的研究，苯丙氨酸是苯丙酮尿症，胃癌和缺血性中风等多种疾病的重要生物标志物。

方法：在本研究中；一种简单，灵敏，选择性和新颖的分析方法，通过使用基于¹³ C苯丙氨酸重同位素的超滤提取方法和LC-MS / MS定量测定人血浆中的苯丙氨酸进行了验证。Amicon®超离心过滤器用于超滤。研究和优化了影响液相色谱分离和MS / MS检测的参数。色谱分离是在Merck SeQuant ZIC-HILIC（100x4.6 mm，5μm）色谱柱上，在柱温为40°C的条件下进行的，其中使用的是含有0.1％甲酸的乙腈和含有0.1％甲酸的水（50 ：50 v / v），流速为0.35 mL / min。m / z 167→121的过渡¹³使用MRM模式监测苯丙氨酸的C苯丙氨酸，m / z 166→120。

结果：该测定的线性浓度范围为0.0025μg/ mL至1.20μg/ mL（R ² = 0.999）。根据FDA指南验证了开发的方法。发现该方法是线性的，灵敏的，精确的，准确的和选择性的。