internal standardization in dispersion systems: an efficient application to determine mg in crude vegetable oils by fs-faas

This study established two sample preparation procedures based on dispersion systems for the determination of mg in crude vegetable oil by is-fs-faas. the emulsions were obtained with 0.10 g of samples [0.5% (m/v)] + 200 μl hno3 [1.0% (v/v)] + 200 μl triton x-100 [1.0% (v/v)] in 16 ml of anhydrous ethanol [80% (v/v)] and 3.50 ml of aqueous phase [17.5% (v/v)], whereas the microemulsions were obtained with 0.10 g of samples [0.5% (m/v)] + 200 μl hno3 [1.0% (v/v)] + 200 μl triton x-100 [1.0% (v/v)] in 18 ml of 1-butanol [90% (v/v)] and 1.50 ml of aqueous phase [7.5% (v/v)]. to overcome non-spectral interference, cd, co, and cu were used as internal standards, and the slopes of calibration curves for mg in 1.0% (v/v) hno3 aqueous solution, anhydrous ethanol + 1.0% (v/v) triton x-100, and 1-butanol + 1.0% (v/v) triton x-100 showed no significant difference at the 95% confidence level using co and cu. calibration curves were obtained by plotting amg/aco and amg/acu vs mg concentration with linear correlation coefficients better than 0.9972 and 0.9986, respectively. the accuracy was evaluated using recovery tests, and recoveries of 98.4–106.6% (is-co) and 93.9–106.9% (is-cu) were obtained. the rsd (n = 5) were 0.4–3.6% (is-co) and 0.3–3.6% (is-cu), and lod were 0.1 μg g−1 (is-co) and 0.2 μg g−1 (is-cu). the content of mg in four crude vegetable oil varied in the range of 8.91 ± 0.30 to 163.88 ± 0.48 μg g−1 for both dispersion systems with rsd < 4.22%.