Song Cuihua, Zhang Shijuan, Ji Zhongyin, Li Yipeng, You Jinmao
Shandong Province Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, PR China.
Shandong Province Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, PR China
J Chromatogr Sci. 2015 Oct;53(9):1536-41. doi: 10.1093/chromsci/bmv049. Epub 2015 May 3.
An accurate and sensitive liquid chromatography-tandem mass spectrometry method was developed for the analysis of amino acids (isoleucine, leucine, valine, tyrosine, phenylalanine and tryptophan) in serum samples using a stable isotope labeling strategy. Amino acid samples and standards were, respectively, derivatized by 10-methyl-acridone-2-sulfonyl chloride (d0-MASC) and its deuterated counterpart d3-MASC to form isotopic pairs which co-eluted and were detected by an MS detector at the same time. Accurate internal standard-based quantification was thereby achieved without the use of any internal standard analogy. The labeling reaction of MASC with amino acids is fast, simple and robust. Besides, derivatization increased the molecular weight of amino acids, and therefore they were shifted out of the background noise which was often observed in low mass region. The instrument LODs were in the range of 1.0-2.5 nmol/L. Linearities calculated by comparing theoretical peak area ratios of d0-/d3-MASC derivatives with the experimental peak area ratios were excellent with correlation coefficients of >0.995. The proposed method was successfully applied to the analysis of amino acids in serum samples with high sensitivity and accuracy.
采用稳定同位素标记策略，建立了一种准确灵敏的液相色谱 - 串联质谱法，用于分析血清样品中的氨基酸（异亮氨酸、亮氨酸、缬氨酸、酪氨酸、苯丙氨酸和色氨酸）。氨基酸样品和标准品分别用10 - 甲基 - 吖啶酮 - 2 - 磺酰氯（d0 - MASC）及其氘代对应物d3 - MASC进行衍生化，形成同位素对，它们共洗脱并同时由质谱检测器检测。从而无需使用任何内标类似物即可实现基于准确内标的定量。MASC与氨基酸的标记反应快速、简单且稳定。此外，衍生化增加了氨基酸的分子量，因此它们从低质量区域经常出现的背景噪声中移出。仪器检测限在1.0 - 2.5 nmol/L范围内。通过比较d0 - /d3 - MASC衍生物的理论峰面积比与实验峰面积比计算得到的线性关系良好，相关系数>0.995。所提出的方法成功应用于血清样品中氨基酸的分析，具有高灵敏度和准确性。
