## 3 Results and Discussions
### HPLC-MS Analysis of Phenolic Compounds  
Following the HPLC-MS analysis carried out in the present study, the following flavonoid compounds were identified in buckwheat seeds and sprouted buckwheat (Tables 2 and 3). The flavonoid quantification, which is presented in Table 4, was performed based on the calibration curves drawn for each compound. The analytical method used was performed according to a previous published article (2019). The precision (intra- and inter-day) was the measure of repeatability of the analytical method under the normal operating conditions, and was verified by six determinations of three concentrations of the standards on the same day (intra-day) and on different days (inter-day), which were carried out and expressed as a percent relative standard deviation (RSD%). The relative standard deviation (RSD) ranged from 1.26% to 4.48% for run-to-run precision and from 1.58% to 32.23% for day-to-day precision. The calibration curves were constructed using six different concentrations in six replicate assays and were expressed by the linear regression coefficient R\({}^{2}\) (line 318-319). The linearity of the method was demonstrated by the correlation coefficient of the whole calibration curve, which was greater than 0.990. \begin{table}
\begin{tabular}{l c c c c} \hline \hline  & **Buckwheat** & **After 3 Days of** & **After 7 Days of** & **Authors** \\  & **Seeds** & **Sprouting** & **Sprouting** & **Authors** \\ \hline TPC, mg GAE/g & 4.91 \(\pm\) 0.15 & 6.14 \(\pm\) 0.22 & & Our study \\ dwb & 3.03 \(\pm\) 0.09 & 8.42 \(\pm\) 0.44 & 22.57 \(\pm\) 0.71 & [31] \\  & 3.23 \(\pm\) 0.14 & 6.70 \(\pm\) 0.12 & & [30] \\ TFC, mg GAE/g & 4.05 \(\pm\) 0.09 & 5.57 \(\pm\) 0.32 & 21.72 \(\pm\) 0.76 & Our study \\ dwb & 4.17 \(\pm\) 0.11 & 11.69 \(\pm\) 0.87 & 21.72 \(\pm\) 0.76 & [31] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: TPC and TFC, the comparison between our study and the studies which were carried out by [PERSON] (2019) and [PERSON] (2019). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Nr.** & \begin{tabular}{c} **Retention** \\ **Time** \\ **t\({}_{\text{R}}\) (min)** \\ \end{tabular} & \
\begin{tabular}{c} **[M-H]\({}^{+}\)** \\ **(m/z)** \\ \end{tabular} &
\begin{tabular}{c} **UV \(\lambda_{\text{max}}\)** \\ **(nm)** \\ \end{tabular} & **Compound Name** \\ \hline
1 & 3.2 & 379, 363 & 280 & Hidrovyseciosolariciresinol (lignan) \\ \hline
2 & 4.7 & 307, 202 & 280 & Epigallocatechin (EGC) \\ \hline
3 & 5.5 & 459, 202 & 280 & Epigallocatechingallat (EGCG) \\ \hline
4 & 7.0 & 459, 202 & 280 & Gallocatechingallat (GCG) \\ \hline
5 & 9.4 & 269, 183 & 240, 300 & Coumestrol _(isoflavonoid)_ \\ \hline
6 & 12.1 & 291, 202 & 280 & Catechin \\ \hline
7 & 12.9 & 363, 247, 163 & 280 & Seciosolariciresinol (lignan) \\ \hline
8 & 14.0 & 449, 287 & 270, 350 & Orientin \\ \hline
9 & 14.5 & 449, 287 & 270, 350 & Isoorientin \\ \hline
10 & 15.4 & 433, 271 & 270, 340 & Vitexin \\ \hline
11 & 16.1 & 611, 475, 303 & 250, 360 & Rutin \\ \hline
12 & 16.4 & 493, 475, 317 & 250, 320 & Isorhamenti glucuronid \\ \hline
13 & 17.7 & 435, 303 & 270, 330 & Quercetin arabinosid \\ \hline
14 & 18.1 & 449, 433, 303 & 270, 330 & Quercetin ramosid (Quercitrin) \\ \hline
15 & 21.9 & 303 & 260, 370 & Quercetin \\ \hline
16 & 23.4 & 317 & 260, 370 & Isorhamenti \\ \hline
17 & 24.3 & 287 & 240, 330 & Luteolin \\ \hline
18 & 25.2 & 271 & 240, 320 & Apigenin \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Retention time, wavelength characteristic of maximum absorption, and ion monitored in MS for phenolic compounds identified in samples.