Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan.
J Sep Sci. 2012 Nov;35(21):2840-6. doi: 10.1002/jssc.201200585. Epub 2012 Sep 24.
A simple and practical derivatization procedure for increasing the detectability and enantiomeric separation of chiral carboxylic acids in LC/ESI-MS/MS has been developed. (S)-Anabasine (ANA) was used as the derivatization reagent and rapidly reacted with carboxylic acids [3-hydroxypalmitic acid (3-OH-PA), 2-(β-carboxyethyl)-6-hydroxy-2,7,8-trimethylchroman (γ-CEHC), and etodolac] in the presence of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholium chloride. The resulting ANA-derivatives were highly responsive in ESI-MS operating in the positive-ion mode and gave characteristic product ions during MS/MS, which enabled sensitive detection using selected reaction monitoring; the detection responses of the ANA-derivatives were increased by 20-160-fold over those of the intact carboxylic acids and the limits of detection were in the low femtomole range (1.8-11 fmol on the column). The ANA-derivatization was also effective for the enatiomeric separation of the chiral carboxylic acids; the resolution was 1.92, 1.75, and 2.03 for 3-OH-PA, γ-CHEC, and etodolac, respectively. The derivatization procedure was successfully applied to a biological sample analysis; the derivatization followed by LC/ESI-MS/MS enabled the separation and detection of trace amounts of 3-OH-PA in neonatal dried blood spot and γ-CEHC in human saliva with a simple pretreatment and small sample volume.
已经开发出一种简单实用的衍生化方法，可提高 LC/ESI-MS/MS 中手性羧酸的检测灵敏度和对映体分离度。（S）-新烟草碱（ANA）被用作衍生化试剂，在 4-（4,6-二甲氧基-1,3,5-三嗪-2-基）-4-甲基吗啉氯化物存在下，与羧酸[3-羟基棕榈酸（3-OH-PA）、2-（β-羧乙基）-6-羟基-2,7,8-三甲基色满（γ-CEHC）和依托度酸]快速反应。所得 ANA 衍生物在正离子模式下的 ESI-MS 中具有高响应性，并在 MS/MS 中给出特征产物离子，从而能够通过选择反应监测进行灵敏检测；与完整羧酸相比，ANA 衍生物的检测响应提高了 20-160 倍，检测限处于低飞摩尔范围（柱上为 1.8-11 fmol）。ANA 衍生化也可有效用于手性羧酸的对映体分离；3-OH-PA、γ-CEHC 和依托度酸的分离度分别为 1.92、1.75 和 2.03。该衍生化方法成功应用于生物样品分析；衍生化后通过 LC/ESI-MS/MS 可以分离和检测新生儿干血斑中痕量的 3-OH-PA 和人唾液中的 γ-CEHC，预处理简单，样品体积小。
