## 2 Results and Discussion
### Method Validation  
The concentrations used for the validation of the linear range were as follows: 0.1, 0.2, 0.5, 1.0, 5.0, 10.0, 20.0, and 100.0 \(\upmu\)g/L for eight target fungicides, while 1.0, 2.0, 5.0, 10.0, 100.0, and 500.0 \(\upmu\)g/L were used for for procymidone. 1.0 \(\upmu\)g/L of nine internal standards, including d\({}_{4}\)-carbendazim, d\({}_{6}\)-thiophanate-methyl, d\({}_{5}\)-pyrimethanail, d\({}_{6}\)-metalaxyl, d\({}_{7}\)-prochloraz, d\({}_{8}\)-dimethomorph, d\({}_{4}\)-triadimefon, and d\({}_{6}\)-difenoconazole, were applied for quantification. Linear regression was performed on the ratios of the sample peak areas to the internal peak areas (Y) versus the mass concentration ratios (C, \(\upmu\)g/L), with correlation coefficients (\(R^{2}\)) above 0.9993 (Table 3). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**Matrix**} & \multicolumn{2}{c}{**Average Peak Area**} & **Absolute Matrix** \\ \cline{3-5}  & & **Standard Solution (A)** & **Post-Spiked (B)** & **Effect (B/A) (\%)** \\ \hline \multirow{3}{*}{**Carbendazim**} & apple & \multirow{3}{*}{\(3.14\times 10^{6}\)} & \(3.01\times 10^{6}\) & 95.9 \\  & orange & & & \(3.11\times 10^{6}\) & 99.0 \\  & grape & & & \(2.97\times 10^{6}\) & 94.6 \\ \hline \multirow{3}{*}{**Thiophanate-methyl**} & apple & \multirow{3}{*}{\(2.81\times 10^{5}\)} & \(2.61\times 10^{5}\) & 92.9 \\  & orange & & \(2.49\times 10^{5}\) & 88.6 \\  & grape & & \(2.53\times 10^{5}\) & 90.0 \\ \hline \multirow{3}{*}{**Pyrimethanail**} & apple & \multirow{3}{*}{\(1.19\times 10^{6}\)} & \(93.0\) \\  & orange & & \(1.23\times 10^{6}\) & 96.1 \\  & grape & & \(1.18\times 10^{6}\) & 92.2 \\ \hline \multirow{3}{*}{**Metalaxyl**} & apple & \multirow{3}{*}{\(2.26\times 10^{6}\)} & \(2.01\times 10^{6}\) & 88.9 \\  & orange & & \(1.98\times 10^{6}\) & 87.6 \\  & grape & & \(2.08\times 10^{6}\) & 92.0 \\ \hline \multirow{3}{*}{**Prochloraz**} & apple & \multirow{3}{*}{\(1.45\times 10^{6}\)} & \(1.37\times 10^{6}\) & 94.5 \\  & orange & & \(1.33\times 10^{6}\) & 91.7 \\  & grape & & \(1.35\times 10^{6}\) & 93.1 \\ \hline \multirow{3}{*}{**Procymidone**} & apple & \multirow{3}{*}{\(1.29\times 10^{4}\)} & \(1.20\times 10^{4}\) & 93.0 \\  & orange & & \(1.18\times 10^{4}\) & 91.5 \\  & grape & & \(1.23\times 10^{4}\) & 95.3 \\ \hline \multirow{3}{*}{**Dimethomorph**} & apple & \multirow{3}{*}{\(2.94\times 10^{5}\)} & \(2.83\times 10^{5}\) & 96.3 \\  & orange & & \(2.85\times 10^{5}\) & 96.9 \\  & grape & & \(2.78\times 10^{5}\) & 94.6 \\ \hline \multirow{3}{*}{**Trialimefon**} & apple & \multirow{3}{*}{\(8.25\times 10^{5}\)} & \(7.14\times 10^{5}\) & 86.6 \\  & orange & & \(7.19\times 10^{5}\) & 87.2 \\  & grape & & \(7.13\times 10^{5}\) & 86.4 \\ \hline \multirow{3}{*}{**Difenoconazole**} & apple & \multirow{3}{*}{\(2.65\times 10^{6}\)} & \(2.42\times 10^{6}\) & 91.2 \\  & orange & & \(2.39\times 10^{6}\) & 90.3 \\ \cline{1-1}  & grape & & \(2.44\times 10^{6}\) & 92.0 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Absolute matrix effect, expressed as the ratio in percentage obtained with a spiked matrix versus neat solvent standards (1.0 \(\upmu\)g/kg, \(n=6\)).