For chocolate sweets, sugar and gummy confectionary, a representative sample was selected by picking the same number of candy or sweets for each colour (e.g. five red, five yellow, five green, five orange, etc.). These samples were homogenised by grinding with dry ice or liquid nitrogen and were kept at −20 °C until analysis.
For validation, samples were fortified and kept overnight at room temperature to allow the optimal mixing of analytes into the respective matrix.
Sugar and gummy confectionary: a 1.00 ± 0.01 g test portion was weighed into a 50 mL beaker and dissolved with 10 mL H2O. Then, 0.1 mL of acetic acid 100% and 10 mL MeCN were added. The pH of this solution had to be between 3.5 and 4.0 (few drops of acetic acid 100% were added as necessary).
Ice-cream and chocolate sweets: 2.00 ± 0.01 g of products were weighed into a 100 mL plastic bottle. Then, 50 mg ± 5 mg of Clara-diastase were added followed by 22.5 g of buffer pH 7.0. The mixture was kept in a thermostatic oven at 40 °C ± 1 °C for 2 h and 30 min. This solution was shaken every 15 min. Next, 0.5 mL of acetic acid 100% were added. The pH of this solution had to be between 3.5 and 4.0 (a few drops of acetic acid 100% were added as necessary). Then, 20 mL of n-hexane and 25 mL of MeOH were added, the bottle was shaken vigorously by hand for 1 min, and centrifuged (2000g for five min at room temperature). The lower phase was clean-up using SPE as described below.