Table 5.

UHPLC-ESI-MS/MS detection of cys.

Derivatization agent	Mobile phase	Stationary phase	Flow rate (mL/min)	T (°C)	Gas flow (L/min)	Gas T (°C)	LOD (fmol)	Refs.
5-AIQC	Gradient elution (ultra-pure water and methanol containing 0.1% formic acid)	C18 (1.8 μm; 2.1 mm × 100 mm)	0.6	50 °C	10	315	4	[57]
AYBA	Gradient elution (0.1% (V/V 1:999) HCOOH and MeOH)	C18 (1.7 μm; 2.1 mm × 100 mm)	0.4	N.D.	3	250	0.0120	[58]

5-AIQC: 5-Aminoisoquinolyl-N-hydroxysuccinimidyl carbamate, AYBA: N-(acridin-9-yl)-2-bromoacetamide, N.D.: not determined, T: temperature.