Which method is most useful when screening for errors of amino and organic acid metabolism?

When screening for errors of amino and organic acid metabolism, electrospray ionization tandem-mass spectrometry (ESI-MS/MS) is particularly advantageous due to its sensitivity, specificity, and ability to analyze small amounts of biological samples. This method enables the simultaneous detection and quantification of various metabolites in a single analysis, making it efficient for identifying abnormalities associated with metabolic disorders.

The ESI process allows ions to be generated from liquid samples, which can then be analyzed in tandem with mass spectrometry to provide detailed information about the structure and quantity of amino acids and organic acids present. This is especially valuable in clinical settings, where prompt and accurate identification of metabolic errors is critical for diagnosis and management.

In comparison, while two-dimensional thin-layer chromatography and gas chromatography are traditional techniques used for analyzing amino and organic acids, they may not provide the same level of sensitivity and throughput as ESI-MS/MS. Inductively coupled plasma-mass spectroscopy is more suited for analyzing elements rather than small organic molecules, making it less relevant for this specific application. Thus, electrospray ionization tandem-mass spectrometry stands out as the most useful method for screening errors in amino and organic acid metabolism.