Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Via P. Bucci Cubo 12/C, 87030, Arcavacata di Rende (CS), Italy.
Anal Bioanal Chem. 2013 Oct;405(25):8267-76. doi: 10.1007/s00216-013-7232-3. Epub 2013 Aug 2.
A new analytical approach, using paper spray tandem mass spectrometry, has been developed for assay of carnitine and acylcarnitines in urine. Paper spray (PS) is a very promising technique, especially in clinical investigations, because of its simplicity, low cost, and rapid sample preparation. A home-made paper spray device was used for assay of urinary acylcarnitines (C2-C18). The performance of solvents with different elution efficiency and paper substrates with different porosity grade and structure were tested by use of spiked synthetic urine. Tandem mass spectrometry in multiple reaction monitoring (MRM) mode was optimized to obtain better specificity and sensitivity. Analyte signals were evaluated for stability and reproducibility. Calibration with [(2)H3]propionylcarnitine (C3-d3), [(2)H3]octanoylcarnitine (C8-d3), and [(2)H3] palmitoylcarnitine (C16-d3) as internal standards was used for quantification. Very good linearity was obtained, with correlation coefficients >0.99 for C0-C12 and C16 acylcarnitines and >0.96 for C14 and C18 acylcarnitines. Accuracy and precision (RSD, %) of the proposed procedure were tested at concentrations of 0.8, 8, and 20 mg L(-1) with very satisfactory results: overall mean accuracy was 98.9% and overall mean relative standard deviation 1%. Limits of detection (LOD) between 6 and 208 μg L(-1) for propionylcarnitine and tetradecanoylcarnitine, respectively, can be regarded as very satisfactory. Application of the method to real urine proved that paper spray tandem mass spectrometry is a simple, rapid, and direct tool (no derivatization is required) for assay of carnitine and C2-C12 acylcarnitines in urine.
一种新的分析方法，使用纸喷雾串联质谱法，已经被开发用于尿液中肉碱和酰基肉碱的测定。纸喷雾（PS）是一种非常有前途的技术，特别是在临床研究中，因为它简单、成本低、样品制备快速。我们使用自制的纸喷雾装置来测定尿液中的酰基肉碱（C2-C18）。通过使用加标合成尿，测试了不同洗脱效率的溶剂和不同孔隙率等级和结构的滤纸基底的性能。采用多重反应监测（MRM）模式对串联质谱进行了优化，以获得更好的特异性和灵敏度。评估了分析物信号的稳定性和重现性。使用[(2)H3]丙酰肉碱（C3-d3）、[(2)H3]辛酰肉碱（C8-d3）和[(2)H3]棕榈酰肉碱（C16-d3）作为内标进行校准，用于定量。得到了非常好的线性关系，C0-C12 和 C16 酰基肉碱的相关系数>0.99，C14 和 C18 酰基肉碱的相关系数>0.96。在 0.8、8 和 20 mg/L 浓度下测试了该方法的准确性和精密度（RSD，%），结果非常令人满意：总体平均准确度为 98.9%，总体平均相对标准偏差为 1%。丙酰肉碱和十四烷酰肉碱的检测限（LOD）分别为 6 和 208 μg/L，可以认为非常令人满意。该方法在实际尿液中的应用证明，纸喷雾串联质谱法是一种简单、快速、直接的工具（不需要衍生化），可用于尿液中肉碱和 C2-C12 酰基肉碱的测定。
