Quantitative acylcarnitine analysis using flow injection analysis tandem mass spectrometry (FIA-MS/MS) is a modern technique used to obtain precise measurements of carnitine and acylcarnitine levels in biological samples such as blood and urine. Carnitine plays a vital role in transporting fatty acids into mitochondria for energy production. Changes in carnitine and acylcarnitine levels are important indicators of certain metabolic and biochemical disorders, such as carnitine deficiency and fatty acid metabolism disorders. This analysis provides accurate information that can aid in early diagnosis and management of metabolism-related conditions.