Acylcarnitine analysis is a useful test for identifying patients with inborn errors of mitochondrial fatty acid β-oxidation and certain organic acidemias. Plasma is routinely used in the diagnostic workup of symptomatic patients. Urine analysis of targeted acylcarnitine species may be helpful in the diagnosis of glutaric acidemia type I and other disorders in which polar acylcarnitine species accumulate. For newborn screening applications, dried blood spot acylcarnitine analysis can be performed as a multiplex assay with other analytes, including amino acids, succinylacetone, guanidinoacetate, creatine, and lysophosphatidylcholines. Tandem mass spectrometric methodology, established more than 30 years ago, remains a valid approach for acylcarnitine analysis. The method involves flow-injection analysis of esterified or underivatized acylcarnitines species and detection using a precursor-ion scan. Alternative methods utilize liquid chromatographic separation of isomeric and isobaric species and/or detection by selected reaction monitoring. These technical standards were developed as a resource for diagnostic laboratory practices in acylcarnitine analysis, interpretation, and reporting.

酰基肉碱分析是识别患有先天性线粒体脂肪酸 β-氧化和某些有机酸血症的患者的有用测试。血浆通常用于有症状患者的诊断检查。目标酰基肉碱种类的尿液分析可能有助于诊断 I 型戊二酸血症和其他极性酰基肉碱种类积累的疾病。对于新生儿筛查应用，干血斑酰基肉碱分析可以与其他分析物（包括氨基酸、琥珀酰丙酮、胍基乙酸盐、肌酸和溶血磷脂酰胆碱）进行多重分析。30 多年前建立的串联质谱方法仍然是一种有效的酰基肉碱分析方法。该方法包括对酯化或未衍生化的酰基肉碱物质进行流动注射分析，并使用前体离子扫描进行检测。替代方法利用液相色谱分离异构体和同量异构体和/或通过选定的反应监测进行检测。这些技术标准是作为酰基肉碱分析、解释和报告中诊断实验室实践的资源而开发的。