## 3 Results  
### Optical Emission Spectra Studies  
An emission spectrum of all the _P. harmala_ seed samples including raw and as-prepared standard samples were recorded at a fixed laser-pulse-energy of 80 mJ. The measured optical-emission-spectrum from laser-produced plasma was obtained with a CCDs array-spectrometer covers the wavelength range varies from 200 to 720 nm. The spectrum was then further studied by identifying the spectral-lines using NIST Database. The emission spectra of _P. harmala_ raw seed sample is given within the wavelength range from 245 nm to 700 nm in Figure 1. The spectral transitions belong to the different elements have various line-intensities which were detected in the raw seed sample. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Element** & **Sample-(\(\alpha\))** & **Sample-(\(\beta\))** & **Sample-(\(\gamma\))** & **Sample-(\(\delta\))** \\  & **(1)** & **(3)** & **(3)** & **(3)** \\ \hline Zinc (Zn) [\(\mu\)g/g] & 0 & 45–55 & 60–65 & 70–80 \\ Mean \(\pm\) SD & 0 & 50 \(\pm\) 2.31 & 62.5 \(\pm\) 1.19 & 75 \(\pm\) 3.15 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Prepared standard samples of P. harmala seeds using zinc as dopant material in \(\mu\)g/g. The optical spectrum indicates weak and strong emission lines of different elements including hydrogen (H), lead (Pb), calcium (Ca), carbon (C), lithium (Li), strontium (Sr), silicon (Si), sodium (Na), iron (Fe), and copper (Cu) along with singly ionized magnesium (Mg II) belongs to the 3d \({}^{2}\)D\({}_{3/2,5/2}\)\(\rightarrow\) 3p \({}^{2}\)P\({}_{1/2,3/2}\) and 3p \({}^{2}\)P\({}_{1/2,3/2}\)\(\rightarrow\) 3s \({}^{2}\)S\({}_{1/2}\) transitions. In addition, a carbon-nitrogen (CN)-diatomic molecular emission band around 388 nm is detected showing the carbon presence in the seed sample. In Figure 2, the optical emission-spectrum of the _P. harmala_ standard doped seed sample-(\(\delta\)) is shown at the same optimized LIBS parameters covers wavelength ranges from 240 to 700 nm. The spectral transitions of different elements having diverse line-intensities were noticed in this spectrum of standard doped seed sample-(\(\delta\)). The optical spectrum of the sample-(\(\delta\)) shows the atomic and ionic-emission-lines of different elements including H, Mg II, Cu, Pb, Si, Sr, C, Fe, Ca, Na, and Li. The emission line of Zn I having a good signal-to-noise ratio (SNR) in this spectral range, appears at 307.59, 328.23, 330.28, 334.53, 468.01, 472.22, 481.05, 280.12, and 636.23 nm, due to 484p \({}^{3}\)P\({}_{1}\)\(\rightarrow\) 4s\({}^{2}\)\({}^{1}\)S\({}_{0}\), 4s4d \({}^{3}\)D\({}_{1}\)\(\rightarrow\) 4s4p \({}^{3}\)P\({}_{0}\), 4d \({}^{3}\)D\({}_{1}\)\(\rightarrow\) 4p \({}^{3}\)P\({}_{1}\), 4d \({}^{3}\)D\({}_{3}\)\(\rightarrow\) 4p \({}^{3}\)P\({}_{2}\), 5s \({}^{3}\)S\({}_{1}\)\(\rightarrow\) 4p \({}^{3}\)P\({}_{0}\), 5s \({}^{3}\)S\({}_{1}\)\(\rightarrow\) 4p \({}^{3}\)P\({}_{1}\), 5s \({}^{3}\)S\({}_{1}\)\(\rightarrow\) 4p \({}^{3}\)P\({}_{2}\), 5d \({}^{3}\)D\({}_{1}\)\(\rightarrow\) 4p \({}^{3}\)P\({}_{2}\), 4d \({}^{1}\)D\({}_{2}\)\(\rightarrow\) 4p \({}^{1}\)P transitions, respectively. A single ionic emission line of zinc (Zn II) is also identified at 255.79 nm due to the 5s \({}^{2}\)S\({}_{1/2}\)\(\rightarrow\) 4p \({}^{2}\)P\({}_{3/2}\) transition. Besides, it is pertinent to mention here that various neutral as well as singly ionized emission lines of Ca at optical wavelengths 315.89, 317.93, 393.37, 396.85, 442.54, 443.50, 445.48, 527.03, 558.20, 558.88, 559.01, 559.45, 559.85, 612.22, 616.13, and 616.2 nm are identified with significantly strong spectral-line-intensities with a good concentration of Ca in seed samples. Moreover, CN-diatomic molecular emission bands around 388 nm are also detected in the doped seed sample-(\(\delta\)) due to the vibrational transitions. In addition, CN-diatomic molecular emissions can also be analyzed in a LIBS spectrum.