In order to enhance the sensitivity and to develop a method suitable for quantification of propylene glycol (PG) in low volume neonate plasma and urine samples, several steps in earlier described high performance liquid chromatographic methods were optimised.
Chromatographic separation on a reversed-phase column and ultraviolet detection resulted in cleaner chromatograms without interfering compounds. Linearity of the standard curves was validated in the concentration range 0.25–50 mg L-1. The lower limit of quantification was 20 times lower than in earlier described methods. Presented method was suitable for quantification of PG concentrations in low volume neonate plasma (15–46 mg L-1) and urine samples (20–175 mg L-1) enabling us to document very low renal versus non-renal contribution of PG clearance in neonates.