Also, the equation obtained by oil-based standard, the linear equation for zinc was Abs = 0.0025 [Zn (lg L1)] 0.0016 (R2 = 0.9998).
In both case the slopes of the calibration curves obtained using either aqueous or oil-based standards are very similar.
This means that zinc present in different edible oil samples can be determined through the calibration technique using either aqueous or oil-based standards.