Table 1. Final LC–MS Parameters Used for the Last Method Development and Validation Steps^a.

	UPLC-MRM/MS
LC eluent	A: H2 0 5% ACN 0.1% FA
	B: ACN 0.1% FA
analytical separation	BEH C18, 2.1 × 50 mm, 1.7 μm, 0.5 mL/min, 5% B, 40 °C on column, 5% B for 0.1 min, 5 to 60% B in 1.9 min, 60 to 98% B in 0.5 min, 98 to 5% B in 0.5 min and 5% B for 0.5 min
ESI parameters	ESI positive mode
	capillary voltage: +3 kV, cone voltage: 48 V
	source at 150 °C, desolvation at 250 °C
	cone gas flow at 150 L/h, desolvation gas at 1000 L/h, collision gas flow at 0.15 mL/min and nebulizer gas at 7 bar
acquisition parameters	MRM mode transitions [m/z]		collision energy
	LC1	896.06 > 807.55	24 V
		896.06 > 982.26	24 V
	SIL-LC1	899.60 > 814.44	24 V
		899.60 > 989.27	24 V
data analyses	Targetlynx v. 4.1
	regression model: linear with 1/x weighting and origin exclusion. Savitzky–Golay smoothing (iterations: 2, width: 2)
	integration using apex track algorithm

^aACN: acetonitrile; ESI: Electrospray ionization; n.a. not applicable.