## 2 Materials and Methods
### Method Validation and Matrix Effect  
The developed method was validated using model wastewater to assess its linearity, recovery, precision, limit of quantification (LOQ), limit of detection (LOD), matrix effects (ME), and uncertainty (U). The method's linearity was assessed by analyzing a series of standard samples with six different concentrations, ranging from LOQ to 1.0 \(\mathrm{\SIUnitSymbolMicro mL^{-1}}\), in both pure solvent and matrix extracts of model wastewater over three consecutive days. The limit of quantification (LOQ) was determined as the lowest spiking level, validated by satisfactory recovery values (70-120%) and RSD (\(\leq\)20%). The limits of detection (LOD) were calculated based on a signal-to-noise ratio of 3. During recovery testing, model wastewater samples free of pharmaceuticals were fortified with appropriate volumes of standard pharmaceutical solutions at concentrations of 0.001, 0.01, and 0.1 \(\mathrm{\SIUnitSymbolMicro mL^{-1}}\). After a one-hour equilibration period, the samples were subjected to the previously described procedure. For each concentration level, five replicates were analyzed. Precision was determined as the relative standard deviation (RSD%) for \begin{table}
\begin{tabular}{l l l l l l l l l l} \hline \hline \multirow{2}{*}{**Pharmaceutical or** **Metabolite**} & \multirow{2}{*}{**Retention**} & \multicolumn{3}{c}{**Quantification**} & \multicolumn{5}{c}{**Confirmation**} \\ \cline{3-10}  & & **MRM** & \multirow{2}{*}{**ER (V)**} & **CE (V)** & **CXP** & **MRM** & \multirow{2}{*}{**EP (V)**} & **CR (V)** & **CXP** \\  & & & **Transition m/z** & & & & **(V)** & **Transition m/z** & & **(V)** \\ \hline Atenol & 2.35 & 267.3 \(>\) 267 & 5 & 35 & 2 & 267.3 \(>\) 133 & 2 & 39 & 4 \\ Bisoprolol & 3.7 & 326.5 \(>\) 116 & 10 & 27 & 8 & 326.74 & 10 & 43 & 12 \\ Candesartan & 5.4 & 441.2 \(>\) 63.2 & 10 & 74 & 17 & 441.2 \(>\) 207.2 & 12 & 54 & 10 \\ Ciprofloxacin & 3.05 & 332 \(>\) 288 & 7 & 25 & 8 & 332.3 \(>\) 314 & 7 & 29 & 8 \\ Doxycycline & 5.25 & 445.1 \(>\) 428 & 10 & 29 & 13 & 445.1 \(>\) 321 & 10 & 42 & 13 \\ Duloxetine & 4.05 & 298.1 \(>\) 44.1 & 3 & 33 & 4 & 298.1 \(>\) 154.2 & 3 & 11 & 4 \\ Esetalopram & 2.2 & 325.1 \(>\) 143 & 15 & 53 & 10 & 325.1 \(>\) 109.1 & 15 & 30 & 10 \\ Fluoxetine & 4.25 & 310.1 \(>\) 148.1 & 11 & 15 & 4 & 310.3 \(>\) 912.1 & 5 & 25 & 2 \\ Indapamide & 3.55 & 366.1 \(>\) 132.2 & 10 & 20 & 7 & 366.1 \(>\) 147.1 & 12 & 18 & 5 \\ Levvorgestrel & 4.75 & 313.3 \(>\) 245.3 & 10 & 25 & 12 & 313.3 \(>\) 96.3 & 8 & 28 & 10 \\ Metformin & 1.55 & 130.1 \(>\) 71 & 4 & 32 & 2 & 130.1 \(>\) 60 & 4 & 19 & 2 \\ Metoprolol & 2.75 & 268 \(>\) 191 & 10 & 27 & 12 & 268 \(>\) 145 & 10 & 35 & 4 \\ Proporafone & 3.95 & 342 \(>\) 116.1 & 8 & 32 & 7 & 342.4 \(>\) 98.1 & 12 & 29 & 6 \\ Ramipril & 4.2 & 417.2 \(>\) 234.2 & 5 & 30 & 3 & 417.2 \(>\) 117.1 & 5 & 57 & 2 \\ Sertlaine & 4.75 & 306.1 \(>\) 159.1 & 7 & 35 & 4 & 306.1 \(>\) 275.1 & 5 & 17 & 4 \\ Torsemide & 3.6 & 349.1 \(>\) 264.1 & 5 & 25 & 3 & 349.1 \(>\) 168.1 & 5 & 66 & 2 \\ Valsartan & 4.65 & 436 \(>\) 235.2 & 7 & 37 & 11 & 436 \(>\) 291.2 & 7 & 23 & 6 \\ Venlafaxine & 3.55 & 278.2 \(>\) 58.1 & 8 & 37 & 4 & 278.2 \(>\) 260.2 & 8 & 17 & 4 \\ Venlafaxine N-oxide & 3.3 & 294 \(>\) 121 & 4 & 30 & 12 & 295 \(>\) 178 & 6 & 24 & 16 \\ Venlafaxine O-desmethyl & 3.1 & 264.1 \(>\) 58.1 & 11 & 31 & 4 & 264.1 \(>\) 246.4 & 11 & 17 & 4 \\ \hline \hline \end{tabular}  
* Q1 and Q2 mass-to-charge ratios (m/z), retention times (RT), entrance potential (EP), collision energy (CE), and collision cell exit potential (CXP).  
\end{table} 
Table 3: MRM parameters for selected pharmaceuticals analyzed using LC-MS/MS. each spiking level. Recoveries were deemed acceptable when falling within the range of 70-120%, with an RSD of no more than 20%.