Beta-hydroxybutyrate and pyroglutamate can be included in a rapid GC-MS screening method for differential diagnosis of metabolic acidosis.

A rapid gas chromatographic mass spectrometric method for measuring anions associated with acute anion gap metabolic acidosis is described. The method is an extension of a previous method. The method quantifies glycolic acid, beta-hydroxybutyric acid with good linearity and pyroglutamic acid with a reproducible curvature relation between 1 and 20 mmol/L and can help the clinician distinguish effectively between ethylene glycol poisoning, alcoholic and diabetic ketoacidosis and cysteine deficiency so early that it will have clinical consequences.