Research Article

E-Cigarette Quality Control: Impurity and Nicotine Level Analysis in Electronic Cigarette Refill Liquids

Table 3

The multiple linear regression of the relative difference in nicotine levels on nicotine-related impurities and total impurities.

Standardized coefficients β

Nicotine-related impurities−0.1070.559
Impurity total−0.1710.349