Stability	Concentration (ng/ml)^a Fresh (zero cycle)	Concentration (ng/ml)^a Found after storage	RSD (%)	Bias^b
Long term: 29 days at −20˚C	1.537	1.553	1.45	1.08
Long term: 29 days at −20˚C	78.713	81.792	2.06	3.91
Short term: 6 h	1.406	1.415	4.75	0.64
Short term: 6 h	85.757	86.108	2.80	0.41
Processed sample (Autosampler): 39 h	1.537	1.525	2.74	−0.76
Processed sample (Autosampler): 39 h	78.713	78.935	3.09	0.28
Processed sample (Dry extract) at RT: 1 h	1.406	1.432	7.17	1.83
Processed sample (Dry extract) at RT: 1 h	87.423	85.492	2.98	−2.21
Processed sample (Dry extract) at −20˚C: 4 days	1.633	1.637	3.56	0.20
Processed sample (Dry extract) at −20˚C: 4 days	82.977	85.100	3.03	2.56
Stock solution, Repaglinide, at RT for 6 h	100	93.850	0.66	−6.15
Stock solution, Repaglinide, at −20˚C for 29 days	100	96.567	0.97	−3.43
Stock solution, IS, at RT for 6 h	100	94.558	1.12	−5.44
Stock solution, IS, at −20˚C for 26 days	100	92.589	0.95	−7.41