Universal electronic-cigarette test: physiochemical characterization of reference e-liquid

Table 1 E-liquid RM homogeneity and stability tests^a

Variable	Sub-sample 1	Sub-sample 2	Sub-sample 3	S.D.	# of liquid phase
Nicotine concentration (mg/ml)
Homogeneity test (1:1)
5 min	10.65	9.19	8.93	0.92	2
20 min	9.90	9.79	9.55	0.17	2
1 h	9.69	10.00	9.78	0.15	1
Homogeneity test (8:2)
5 min	10.41	10.29	10.23	0.31	2
20 min	10.48	10.53	11.82	0.66	2
1 h	10.89	10.61	11.00	0.20	1
Homogeneity test (2:8)
5 min	9.28	8.49	7.98	0.59	2
20 min	9.63	8.44	9.63	0.64	2
1 h	9.73	9.36	8.33	0.73	1
3 h	9.54	8.91	9.14	0.32	1
6 h	10.99	9.88	11.18	0.70	1
Stability test (1:1) (thermocycler)
24 h	9.97	10.02	10.00	0.02	1
72 h	9.98	10.04	10.05	0.03	1
Absorbance (490 nm)
Stability test (1:1) (spectrophotometer)
Day 0	11.99	12.12	12.13	1	1
1 month	26.29	26.08	25.95	2.14	1
6 month	200.84	198.28	188.69	16.20	1

^a1:1 propylene glycol/glycerin = 50% propylene glycol and 50% glycerin by volume prepared using mass
8:2 propylene glycol/glycerin = 80% propylene glycol and 20% glycerin by volume prepared using mass
2:8 propylene glycol/glycerin = 20% propylene glycol and 80% glycerin by volume prepared using mass

ISSN: 1617-9625