Table 5.

Stability data for 2-dC, 5-mdC and 5-hmdC in negative Control.

Compound Name	Stability Test	Nominal Concentration (ng/ml)	Observed Concentration (Mean ± SD)	Accuracy (RE %)	Precision (CV %)
2-dC	Auto-Sampler (4°C, 24h)	15	14.03 ± 0.66	−6.5	4.71
		500	494 ± 12	−1.2	2.43
		4000	3990 ± 264.56	−0.25	6.63
	Bench top (6 h)	15	12.98 ± 0.74	−13.5	5.71
		500	447 ± 16.52	−13.5	5.71
		4000	3673 ± 61.10	−8.17	1.66
	Freeze and thaw (−80°C to 4°C, 3 cycles	15	15.65 ± 0.37	4.33	2.36
		500	511.3 ± 9.02	2.27	1.76
		4000	4280 ± 51.96	7	1.21
	Long-term (−80°C, 10 days)	15	16.02 ± 0.46	6.83	2.85
		500	516 ± 10.15	3.20	1.97
		4000	4260 ± 175.7	6.50	4.13
5-mdC	Auto-Sampler (4°C, 24 h)	1.5	1.39 ± 0.04	−7.16	3.18
		50	51.97 ± 0.51	3.93	0.99
		400	409.7 ± 30.62	2.42	7.47
	Bench top (6 h)	1.5	1.29 ± 0.11	−14	8.39
		50	42.86 ± 1.83	−14.27	4.28
		400	345 ± 2.65	−13.75	0.77
	Freeze and thaw (−80°C to 4°C, 3 cycles	1.5	1.59 ± 0.03	5.67	1.59
		50	52.5 ± 2.23	5.00	4.26
		400	395 ± 5.20	−1.25	1.32
	Long-term (−80°C, 10 days)	1.5	1.63 ± 0.09	8.3	5.38
		50	51.57 ± 2.64	3.1	5.12
		400	414 ± 19.97	3.5	4.82
5-hmdC	Auto-Sampler (4°C, 24 h)	0.15	0.15 ± 0.01	−1.7	9.33
		1	0.99 ± 0.05	−1.5	5.16
		8	7.79 ± 0.55	−2.6	7.06
	Bench top (6 h)	0.15	0.13 ± 0.02	−16.22	12.34
		1	0.87 ± 0.04	−13.00	5.01
		8	7.2 ± 0.16	−10.04	2.21
	Freeze and thaw (−80°C to 4°C, 3 cycles	0.15	0.15 ± 0.01	0.67	4.59
		1	1.10 ± 0.05	10.33	4.56
		8	9.10 ± 0.10	13.79	1.04
	Long-term (−80°C, 10 days)	0.15	0.17 ± 0.02	12	10.14
		1	0.96 ± 0.02	−3.8	1.73
		8	8.57 ± 0.34	7.08	3.91