Table 3.

Stability results for ManNAc and Neu5Ac in LQC (5% BSA) and in HQC (human plasma).

ManNAc	LQC (30.0 ng/mL)	HQC (4051 ng/mL)
	Deviation (%)	Deviation (%)
Room temperature for 16 h	8.4	−7.8
Freeze/thaw 4 cycles	1.1	0.3
Autosampler at 2–8 °C for 48 h	8.5	−4.7
Processed sample at 2–8 °C for 48 h	0.0	−1.6
Long-term at −80 °C for 310 days	2.2	2.4

Neu5Ac	LQC (75.0 ng/mL)	HQC (8159 ng/mL)
	Deviation (%)	Deviation (%)
Room temperature for 16 h	−0.6	−6.2
Freeze/thaw 4 cycles	0.2	−5.8
Autosampler at 2–8 °C for 96 h	−1.6	1.8
Processed sample at 2–8 °C for 48 h	10.1	−11.1
Long-term −80 °C for 309 days	3.6	−5.8