Determination of vitamin B 5 in human urine by high‐performance liquid chromatography coupled with mass spectrometry

In the present work, we have developed a simple and rapid liquid chromatography/mass spectrometry (LC/MS) method for the identification and quantification of vitamin B 5 in human urine. Urine was spiked with vitamin B 5 internal standard, hopantenic acid (HOPA), and then diluted with the LC mobile phase prior to its analysis by LC/MS. The quantification was performed in single ion monitoring mode. The calibration curve was linear ( r   2 = 0.999) between 0.25 to 10 μg/mL. With a limit of detection of 0.1 μg/mL the method was sensitive enough to determine low levels of vitamin B 5 in urine. The overall quantitative efficiency of the method was evaluated by spiking urine samples with four different concentrations of vitamin B 5 ; the intra‐assay coefficient of variation was below 5% and the recoveries were between 96 to 108%. The results of the present study show that the proposed method is selective and sensitive enough for the quantification of vitamin B 5 in urine.