# Resveratrol: A Review on the Biological Activity and Applications
## 18 UHPLC-MS Analysis of \(t\)RSV in Romanian Wines
### Uhplc-Ms Analysis
This suggests that the UHPLC-MS method provides high specificity, primarily due to the mass detection at \(m/z\) 227, ensuring that the observed peak can be confidently attributed to \(t\)RSV without interference from other substances. Such specificity is critical for accurate quantification in complex matrices like wine (Figure 3). In addition to the distinct peak at the specific retention time (RT), the confirmation of \(t\)RSV in the samples was further substantiated by comparing the mass spectrum obtained between \(m/z\) 100 and 400. This range was meticulously examined to match the ionization pattern of the \(t\)RSV reference with the sample peaks. By ensuring that the spectra of the samples aligned with that of the reference \(t\)RSV, particularly the peak at \(m/z\) 227, the presence of \(t\)RSV could be confirmed with greater certainty. This comparative approach across the broad mass range enhances the reliability of the identification, ruling out the possibility of coincidental matches or false positives that might arise from other compounds eluting at similar RTs (Figure 4). \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Values** \\ \hline Linearity range [ng/mL] & 15.259–244.141 \\ \(R^{2}\) & 0.9979 \\ Equation & \(Y=181.7X-197.6\) \\ LOD [ng/mL] & 16.197 \\ LOQ [ng/mL] & 49.081 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of calibration curve parameters for _trans_-resveratrol quantification. Figure 2: Calibration curve of _trans_-resveratrol displaying the detector response across a range of standard concentrations. In Figure 4, we observe the elution profiles of four different wine samples labeled W1 through W4. Each chromatogram is overlaid to facilitate comparison, particularly focusing on the \(t\)RSV peak. For all samples, the \(t\)RSV peak was identified at the same RT, which is consistent with the reference peak, suggesting successful identification of \(t\)RSV in each wine. The peak intensities vary among the wine samples, which may reflect the different concentrations of \(t\)RSV in each type of wine. The RT's consistency across all samples is a good indicator of the method's reproducibility. Furthermore, the distinct peaks observed for \(t\)RSV in each sample, without interference from other peaks, confirm the specificity  
Figure 4: Mass spectrum of _trans_-resveratrol illustrating the quantification of molecular ion peak at \(m/z\) 227, used for both confirmation and quantification of the analyte. Figure 3: Chromatogram of a _trans_-resveratrol standard showing a prominent peak at 9.67 min, indicative of its purity and concentration in the reference sample. of the method, especially considering the mass detection confirmation at \(m/z\) 227. This comparative display allows for a visual assessment of the presence and relative quantity of \(t\)RSV across the different wine samples, providing an at-a-glance understanding of how \(t\)RSV concentrations may differ between white wines and RWs, as well as among different varieties. The clean baselines and sharp peak shapes are indicative of a well-optimized UHPLC method, essential for accurate quantification and comparison between samples (Figure 5). Sample W1 (Feteasca Regala variety) registers the highest concentration of \(t\)RSV among the white wines, suggesting that this varietal may naturally accumulate more of this compound or that the vinicitation methods have been conducive to its retention. Moving to W3 (Dry Muscat variety), we can see that the \(t\)RSV content is significantly lower, which may reflect inherent varietal differences or distinct processing techniques affecting the final \(t\)RSV levels. When looking at the RWs, W2 (Feteasca Neagra variety) contains the highest concentration of \(t\)RSV in the selection, aligning with the general observation that RWs often have higher levels of \(t\)RSV due to the extended contact with grape skins during fermentation, which typically enriches the wine with more phenolic compounds.