Background: Drugs residual discharge into the environment through municipal and hospital wastewaters is one of the emergent environmental problems. Imipenem as a professional hospital antibiotic is widely used against gram- positive and negative bacteria and with entrance to the aquatic environments could prompt a lot of risks such as bacteria resistance, allergies, spoiling alga and daphnia and interrupting in wastewater treatment processes. Therefore there is a command to develop a method for extraction and determination of Imipenem from hospital sewage.

Materials and Methods: Solid phase extraction (SPE) was used to extract Imipenem from samples. Recovery percentage calculated at different pH of 3 and 7. The extracted samples analyzed by High Performance Liquid Chromatography (HPLC) equipped with UV detector. HPLC operated using borate buffer/methanol as mobile phase at flow rate of 0.7 ml/min, column temperature of 20 °C, and UV wavelength of 280-300 nm.

Results: Maximum recovery percentage was obtained 68% at pH=7. The best condition for HPLC was 80:20 ratio of borate buffer/methanol with pH=7.5 and at UV wavelength of 300 nm. Linearity calculated 0.9829, primary and intermediate precision both were more than 95%. Limit of detection (LOD) and limit of quantification (LOQ) were 3 and 10 µg/l respectively.

Conclusion: The method could simply and with significant reliability be applied to extract and determinate Imipenem in complex hospital wastewater matrixes.