## 2 Results and Discussion
### Validation of the Quantitative Method  
#### 2.2.1 Linearity of Calibration Curve in Different Wine Matrix  
Many reports have investigated the effect of non-volatile compounds on the perception of aroma compounds in wine, such as residual sugar, ethanol content, polyphenol, total acidity and so on [21; 22; 23]. Calibration curves performed in a synthetic matrix may not be representative of measurements taken in wines with diverse non-volatile compounds. In this study, two kinds of white wines with distinct different residual sugar contents were chosen as base wines for the calibration curves; Low wine (L) base for lower residual sugar content (3.7 g/L) and High wine (H) base for higher residual sugar content (64.1 g/L). These wines were found to appropriate to determine the effect of the non-volatile matrix on all wines measured in this study (data not shown). As can be seen in Table 1, there were some differences between the two kinds of calibration curves, especially for compounds of limonene and rose oxide isomers, thus two calibration curves were used in this study. Wines with corresponding residual sugar measurements were matched to the appropriate calibration curve. Wines with residual sugar content less than 19 g/L used the L calibration curve, while H calibration curve was used if the residual sugar content was greater than 19 g/L. The choice of 19 g/L as the dividing point was set based on spiked recovery study of wines with diverse residual sugar content (Table 2). \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Compounds 1**} & \multirow{2}{*}{**ISTD 2**} & \multirow{2}{*}{**Ions Chosen 3**} & \multicolumn{3}{c}{**De-aromatized Low (L) Base 5**} & \multicolumn{3}{c}{**De-aromatized High (H) Base 5**} \\ \cline{5-10}  & & & **L first 4** & **L middle 4** & **L last 4** & **H first 4** & **H middle 4** & **H last 4** \\ \cline{5-10}  & & & **Slope** & **Slope** & **Slope** & **Slope** & **Slope** & **Slope** \\ \hline
2 & 1 & **107**, 121, 136 & 0.21 \({}^{\text{a}}\) & 0.12 \({}^{\text{b}}\) & 0.10 \({}^{\text{b}}\) & 0.14 \({}^{\text{a}}\)  
\begin{table} \begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multirow{3}{*}{**Compounds**} & \multirow{3}{*}{**LOD**} & \multirow{3}{*}{**LOQ**} & \multirow{3}{*}{**in PG**} & \multicolumn{3}{c}{**Spiked Recovery (\%)**} & \multicolumn{3}{c}{**Riesling**} & \multicolumn{1}{c}{**Pinot Gris**} & \multicolumn{1}{c}{**Standards**} \\ \cline{3-13}  & & & **in PG** & **in PG** & **in RS** & **in RS** & **medium** & **in RS** & **Reproducibility** & **Reproducibility** & **Stability** \\  & & & & **Dy 1** & **Dy 2** & **Dy 3** & **Dy 4** & **Sweet 1** & **Sweet 2** & **(RSD) 3** & **(RSD) 3** \\ \hline
2 & 0.10 & 0.34 & 106 & 94 & 90 & 87 & 103 & 114 & 15.60 & 0.00 & 12.1 \\
4 & 0.08 & 0.27 & 104 & 93 & 93 & 111 & 106 & 112 & 15.91 & 0.00 & 11.1 \\
5 & 0.0002 & 0.001 & 101 & 129 & 119 & 135 & 137 & 119 & 0.00 & 0.00 & 15.2 \\
6 & 0.0003 & 0.001 & 99 & 112 & 132 & 103 & 125 & 105 & 12.98 & 0.00 & 13.0 \\
7 & 0.73 & 1.09 & 72 & 102 & 90 & 118 & 110 & 97 & 18.35 & 17.27 & 10.7 \\
8 & 0.44 & 0.70 & 72 & 101 & 93 & 112 & 113 & 97 & 18.13 & 14.29 & 11.0 \\
9 & 0.001 & 0.003 & 99 & 116 & 126 & 113 & 120 & 123 & 0.00 & 0.00 & 12.9 \\
10 & 0.0006 & 0.002 & 94 & 102 & 114 & 118 & 110 & 114 & 15.57 & 0.00 & 12.8 \\
11 & 0.28 & 0.93 & 76 & 103 & 103 & 116 & 118 & 100 & 15.12 & 0.00 & 15.6 \\
12 & 0.33 & 1.11 & 72 & 100 & 97 & 115 & 114 & 96 & 0.00 & 15.26 & 12.8 \\
14 & 0.03 & 0.12 & 101 & 98 & 106 & 101 & 102 & 103 & 0.00 & 0.00 & 9.5 \\
16 & 0.08 & 0.25 & 102 & 100 & 109 & 98 & 101 & 102 & 12.57 & 0.00 & 9.5 \\
18 & 0.19 & 0.62 & 100 & 96 & 112 & 104 & 107 & 102 & 13.35 & 14.21 & 4.3 \\
20 & 0.15 & 0.49 & 98 & 95 & 106 & 101 & 103 & 102 & 14.85 & 16.00 & 4.8 \\
21 & 0.02 & 0.08 & 98 & 103 & 96 & 81 & 108 & 107 & 15.60 & 11.01 & 15.0 \\ \hline \hline \end{tabular}