## 3 Results and Discussion  
### Dissolution Procedures  
In order to find the optimum digestion protocol for hard candies and jellies samples, multiple wet acid methods using double de-ionized water, concentrated HNO\({}_{3}\) and H\({}_{2}\)O\({}_{2}\) were evaluated. For this purpose, 0.5 g of the samples (CS-2 for hard candies and JS-4 for jellies) were placed in a PTFE beaker, followed by the addition of the digestion mixture and heating. The final digests were transferred to volumetric flasks of 25 mL and their volume was made up to the mark using double de-ionized water. Table 2 summarizes the visual observations for the digestion protocols that were examined in order to achieve complete decomposition of the solid sample. It was observed that H\({}_{2}\)O\({}_{2}\) and double de-ionized H\({}_{2}\)O could not decompose the sample completely in the absence of an oxidizing agent. At room temperature, approximately 2 h were required for the complete decomposition of 0.5 g of the jelly samples, while hard candies were decomposed at approximately 1 h when 5 mL of conc. HNO\({}_{3}\) were used as the oxidizing agent. The addition of H\({}_{2}\)O\({}_{2}\) could assist the digestion procedure. As such, when 3 mL of conc. HNO\({}_{3}\) and 2 mL of conc. H\({}_{2}\)O\({}_{2}\) were used as the digestion mixture, the jelly and hard candy samples were completely decomposed at approximately 60 min and 30 min, respectively.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Digestion Mixture** & **Digestion Temperature** & **Approximate** & **Observation for Hard** & **Observation for Jellies** \\  & (\({}^{\circ}\)C)** & **Digestion Time (min)** & **Candies** & **Observation for Jellies** \\ \hline
5 mL conc. HNO\({}_{3}\) & Room temperature & 60 & Clear solution & Partial dissolution \\
5 mL conc. HNO\({}_{3}\) & Room temperature & 120 & Clear solution & Clear solution \\
5 mL conc. H\({}_{2}\)O\({}_{2}\) & Room temperature & 60 & Clear colored solution & Partial dissolution \\
5 mL conc. H\({}_{2}\)O\({}_{2}\) & Room temperature & 120 & Clear colored solution & Clear colored solution \\
3 mL conc. HNO\({}_{3}\) & Room temperature & 30 & Clear solution & Partial dissolution \\
2 mL conc. H\({}_{2}\)O\({}_{2}\) & & & & \\
3 mL conc. HNO\({}_{3}\) & Room temperature & 60 & Clear solution & Clear solution \\
2 mL conc. H\({}_{2}\)O\({}_{2}\) & & & & \\
5 mL H\({}_{2}\)O\({}_{2}\) & & & & \\
3 mL conc. HNO\({}_{3}\) & 120 & \(<\)10 & Clear solution & Clear solution \\
5 mL conc. HNO\({}_{3}\) & 120 & \(<\)10 & Clear solution & Clear solution \\
3 mL conc. HNO\({}_{3}\) & & & & \\
2 mL conc. H\({}_{2}\)O\({}_{2}\) & & & & \\
5 mL conc. HNO\({}_{3}\) & & & & \\
2 mL conc. H\({}_{2}\)O\({}_{2}\) & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Dissolution tests for the digestion of hard candies and jellies (0.5 g sample).  
Figure 1: Schematic representation of the experimental procedure.  
In order to further increase the sample preparation time, boiling of the sample was employed. As such, the jelly and hard candy samples were completely decomposed in less than 10 min by the addition of 3 mL of conc. HNO\({}_{3}\) at 120 \({}^{\circ}\)C. As a result, in order to ensure the minimum sample preparation time and the minimum consumption of chemicals, digestion of hard candies and jellies was performed by the addition of 3 mL of conc. HNO\({}_{3}\) in a beaker containing 0.5 g of sample, followed by heating at 120 \({}^{\circ}\)C for approximately 10 min. Moreover, lower consumption of chemicals was required compared with previous studies for the candy samples [4].