Jiang Wen-Ting, Tang Liu-Xing, Pan Jie, Su Cun-Jin, Shen Zhu, Hu Zhan-Hong, Zhan Zhou-Bing, Shi Ai-Ming
Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China.
Department of Nephrology, The Second Affiliated Hospital of Soochow University, Suzhou, China.
Ann Transl Med. 2022 Jan;10(2):103. doi: 10.21037/atm-21-6784.
L-carnitine is an endogenous vitamin-like amino acid derivate which plays an essential role in energy metabolism and can be easily lost via dialysis. Deficiency of L-carnitine has great effects on many aspects of bodily functions. To determine the deficiency degree and adjust the supplementation dose, a rapid, sensitive, and specific method for the detection of endogenous L-carnitine in the plasma of dialysis patients using ultra-high performance liquid chromatography-Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-HRMS) was developed and validated.
The plasma samples were processed by protein precipitation and centrifugation before analysis using UHPLC-Orbitrap-HRMS. Sample separation was achieved with a hydrophilic interaction liquid chromatography (HILIC) column, using an isocratic elution with a runtime of 5 min. The separated analytes were detected by positive ionization mode in full scan mode and targeted-single ion monitoring (t-SIM) mode. Mildronate was used as the internal standard (IS).
All the plasma could be detected in the range of 6.169 to 197.394 µM, with adequate accuracy, precision, and recovery. The method was validated in fortified validation with relative standard deviations (RSD) 5.15-8.74%. This method was applied to the analysis of 105 dialysis patients and 39 healthy participants, the results revealed that peritoneal dialysis patients without L-carnitine supplementation should pay more attention to L-carnitine monitoring, meanwhile, all the hemodialysis patients were advised to be routinely given a full dose of L-carnitine, no matter whether they had taken L-carnitine or not.
This study developed a simple and rapid UHPLC-Orbitrap-HRMS method for detection of endogenous L-carnitine in dialysis patients, which could be useful to promote rational drug use.
左旋肉碱是一种内源性类维生素氨基酸衍生物，在能量代谢中起重要作用，且可通过透析轻易丢失。左旋肉碱缺乏对身体功能的多个方面有重大影响。为确定缺乏程度并调整补充剂量，开发并验证了一种使用超高效液相色谱-轨道阱高分辨率质谱法（UHPLC-Orbitrap-HRMS）检测透析患者血浆中内源性左旋肉碱的快速、灵敏且特异的方法。
血浆样本在使用UHPLC-Orbitrap-HRMS分析前通过蛋白沉淀和离心进行处理。使用亲水作用液相色谱（HILIC）柱进行样品分离，采用等度洗脱，运行时间为5分钟。分离的分析物通过正离子模式在全扫描模式和靶向单离子监测（t-SIM）模式下进行检测。米多君用作内标（IS）。
所有血浆在6.169至197.394μM范围内均可检测到，具有足够的准确性、精密度和回收率。该方法在强化验证中得到验证，相对标准偏差（RSD）为5.15 - 8.74%。该方法应用于105例透析患者和39名健康参与者的分析，结果显示未补充左旋肉碱的腹膜透析患者应更加关注左旋肉碱监测，同时，建议所有血液透析患者常规给予全剂量的左旋肉碱，无论他们是否服用过左旋肉碱。
本研究开发了一种简单快速的UHPLC-Orbitrap-HRMS方法用于检测透析患者的内源性左旋肉碱，这可能有助于促进合理用药。
