HILIC-MS/MS-based strategy for quantitative amino acid profiling in multiple biological matrices and its application...

Amino acid metabolism disorders have strong links to various kidney diseases, and the kidney is essential for maintaining systemic amino acid homeostasis. Given the lack of obvious clinical symptoms in the early stages of kidney disease, searching for reliable metabolic biomarkers is essential for early diagnosis. Endogenous AAs are widely present in human biological matrices, making it difficult to obtain analyte-free blank matrices for method validation. This poses challenges in the preparation of calibration standards, leading to uncertainty and reduced consistency in the results. This study aimed to develop a rapid hydrophilic interaction liquid chromatographic method coupled with tandem mass spectrometry. It could analyze 47 amino acids and related compounds, present in various biological matrices (human plasma, urine, and cyst fluids). The calibration curves were constructed by stripping each matrix to obtain a surrogate matrix. The slopes of the different calibration curves were systematically evaluated and the analytical results were compared with results obtained through the method of standard addition. The calibration curves established using both the standard addition method and the matrix stripping method were parallel, hence matrix stripping effectively mitigates matrix effects under a variety of matrix conditions, thereby assuring the accuracy and reliability of quantitative analysis results. To further investigate the applicability of this method to large-scale sample analysis, the analysis of plasma samples and urine samples obtained from patients with two types of kidney disease was performed.