7683b auto injector

The limonene loading content in the films was determined using GC-MS (Agilent-Technologies 6890N network gas chromatographic system combined with Agilent-Technologies 5973 inert XL mass selective detector and Agilent-Technologies 7683B auto-injector, Little Falls, CA, USA). The films were cut into a 50 mm² area and their weights were recorded. They were then cut into small pieces. Limonene was extracted from the films by soaking them in 5 mL ethanol for 24 h. The extracted solution was diluted to 100 µg/mL (theoretical concentration was calculated by the weight of each film). Each sample was analyzed in triplicate. Limonene content was determined from the standard curve of limonene in absolute ethanol, which was linear with a high correlation coefficient (r² = 0.9988). The following regression equation was obtained: y = 169867x − 397775, where y is the peak area and x is the concentration of limonene (mg/L). The limonene loading was calculated using the following equation:
$\mathrm{Limonene}\mathrm{loading}\mathrm{content}(\%)=\frac{\mathrm{Aq}\left(\mathrm{g}\right)}{\mathrm{C}\left(\%\frac{\mathrm{w}}{\mathrm{w}}\right)\times \mathrm{W}\left(\mathrm{g}\right)}\times 100$
where Aq is the actual quantity of limonene present in the film (g), C is the concentration of limonene (%w/w), and W is the film weight (g).