Table 5.

Stability of six BAs.

	QC Samples				Extraction Samples
	Storage Condition/Temperature	Storage Condition/Period	QC Levels	RSD%	RSD%
KBA		6 h	L	1.52	2.53
			M	3.40
			H	3.11
	4 °C	9 h	L	2.59
			M	4.37
			H	4.05
	−80 °C	12–16 h	L	1.08
			M	2.76
			H	4.43
	4 °C	30 days	L	3.92
			M	2.44
			H	1.67
AKBA	25 °C	6 h	L	3.03	3.46
			M	3.52
			H	4.56
	4 °C	9 h	L	1.91
			M	2.33
			H	2.53
	−80 °C	12–16 h	L	4.78
			M	3.42
			H	2.03
	4 °C	30 days	L	2.72
			M	3.30
			H	4.17
α-BA	25 °C	6 h	L	3.00	2.72
			M	1.35
			H	4.02
	4 °C	9 h	L	2.31
			M	4.28
			H	3.96
	−80 °C	12–16 h	L	4.39
			M	2.88
			H	2.05
	4 °C	30 days	L	1.22
			M	3.64
			H	3.35
β-BA	25 °C	6 h	L	2.92	4.39
			M	1.69
			H	4.87
	4 °C	9 h	L	1.32
			M	3.77
			H	2.33
	−80 °C	12–16 h	L	2.10
			M	3.81
			H	1.54
	4 °C	30 days	L	4.00
			M	1.79
			H	2.85
α-ABA	25 °C	6 h	L	2.66	2.10
			M	4.23
			H	2.05
	4 °C	9 h	L	3.48
			M	1.77
			H	2.91
	−80 °C	12–16 h	L	3.08
			M	4.33
			H	1.59
	4 °C	30 days	L	2.70
			M	4.40
			H	3.81
β-ABA	25 °C	6 h	L	4.74	4.21
			M	2.90
			H	3.21
	4 °C	9 h	L	1.68
			M	2.03
			H	2.47
	−80 °C	12–16 h	L	3.88
			M	1.96
			H	4.07
	4 °C	30 days	L	2.85
			M	2.72
			H	1.29

L: LQC levels, M: MQC levels, H: HQC levels.