Biomarker Profiling for Pyridoxine Dependent Epilepsy in Dried Blood Spots by HILIC-ESI-MS

Table 2

Results of stock solution stability for alpha-amino adipic semialdehyde/piperidine-6-carboxylic acid and pipecolic acid.

Stock solution stability
	AASA/P6C		PA
Time points (hours)	Mean back calculated concentration (SD) (mcg/mL)	% change	Mean back calculated concentration (SD) (mcg/mL)	% change
0	0.89 (0.04)	0.00	0.85 (0.01)	0.00
2	0.89 (0.06)	0.05	0.85 (0.01)	0.00
4	0.90 (0.01)	0.45	0.78 (0.03)	-7.84
6	0.91 (0.1)	1.79	0.80 (0.03)	-6.10
8	0.91 (0.007)	1.43	0.79 (0.03)	-6.87
P value	0.138		0.007

Values expressed as mean (SD); statistical treatment performed using repeated measures ANOVA. p value < 0.05 was considered significant. AASA: alpha-amino adipic semialdehyde, P6C: piperidine-6-carboxylic acid, and PC: pipecolic acid.