Development of an automated LC-MS/MS method for the determination of eight pharmaceutical compounds in wastewater

An analytical method for the determination of eight pharmaceutical compounds in waters has been developed and validated. Target compounds included hormones, non-steroidal anti-inflammatory drugs, antibiotics, β-blockers and psychiatric drugs. The analytical determination has been achieved through off-line solid phase extraction and analysis in liquid chromatography coupled with mass spectrometry. For the determination of the hormones, samples were also derivatized with 1,2-dimethylimidazole-4-sulfonyl-chloride. The limits of detection of the drugs varied between 0.01 and 30 ng/L, according to the limits indicated by the European Commission. For each compound, the six-point calibration curves showed excellent linearity (r2 ≥ 0.995) and the inter-session repeatability for all compounds ranged from 1 to 10%. This method was also applied for the determination of the target pharmaceuticals in the influent and the effluent of a wastewater treatment plant in order to assess their presence and their removal inside the plant. Every compound, except for 17-α-ethinylestradiol, has been found in the influent of the wastewater treatment plant and none of them, except for acetaminophen, were removed within the plant.