Table 5. Method validation for phospholipid and cholesterol analysis

		Linearity			Sensitivity
		Calibration curve	Calibration range (μg/mL)	Coefficient of determination (R2)	LOD (μg/mL of solvent)1)	LOQ (μg/mL of solvent)2)
Phospholipid	PE3)	y = 14.212x2 + 11656x - 62,7274)	1.95-500	0.9998	0.50	1.2
	PC3)	y = 16.22x2 + 8064x - 25,1494)	1.95-500	0.9999	0.28	0.84
	SM3)	y = 11.72x2 + 9011x - 27,2954)	1.95-500	0.9998	0.22	0.63
Cholesterol		y = 10.416x - 0.03235)	12.5-400	0.9998	0.18	0.91

LOD, limit of detection.
LOQ, limit of quantification.
PE, phosphatidylethanolamine; PC, phosphatidylcholine; SM, sphingomyelin.
The calibration curve was expressed as y = ax²+ bx + c, where represents the peak area and x denotes the concentration (μg/mL).
The calibration curve was expressed as y = ax + b, where represents the peak area and x denotes the concentration (μg/mL).