Abstract
Electrospray ionization tandem mass spectrometry enables us the sensitive and quantitative analysis of many ionic compounds with high polarity, such as acylcarnitines and amino acids. In newborn screening programs using this new technology, many inborn errors of metabolism can be diagnosed simultaneously by the measurement of one small punch of blood spots. Quality of life of patients with target diseases is thought to be improved by early medical intervention to prevent sudden death in infancy or brain damage. Based on the limitation of this program recognized, methodological difficulties to be overcome in view of the false negative and false positive rate and modifications in our program are described.
