COVID-19 ve Yeniden Ortaya Çıkan İnfluenza Tipi Virüslerin Tedavisinde Kullanılan Favipiravirin İzotopik Türevlerinin Sentezlenmesi ve Kan, İdrar, Atık Su Örneklerinde Eser Seviyelerde Tayini (Synthesis of Isotopic Derivatives of Favipiravir Used in the Treatment of COVID-19 and Re-emerging Influenza Type Viruses and Its Determination at Trace Levels in Blood, Urine and Wastewater Samples)